Summary

Getting good cold start performance in your tuning is one of the factors that really makes a difference in a daily driven vehicle. In this webinar we’ll be investigating the cold start tuning process on the ECU Master EMU Black ECU, using our V11 Subaru STi.

Timestamps

1:30 - Why we need cold start enrichment

3:25 - Tune your VE table first

6:45 - Considerations

9:00 - Ecumaster software overview

10:45 - Engine start parameters

13:05 - Cranking fuel tables

16:55 - Fuel TPS scale

17:20 - Prime pulse

18:05 - After start enrichment

20:45 - Warm-up enrichment

22:10 - Idle control

25:00 - Startup demonstration

30:00 - Questions

Transcript

- Hey guys, Andre from High Performance Academy here, welcome along to another one of our webinars. This time we're going to be talking about cold start tuning using the Ecumaster EMU Black platform. Cold start tuning I think is one of the most important aspects, particularly when it comes to tuning street driven cars, really sets apart a poor quality tune that's difficult to get the car to start and idle properly when it's cold from one that replicates factory drivability and for me this is really what I'm trying to do when I tune a street driven car. I'm trying to get the drivability and performance of the engine to replicate what we'd expect from a brand new factory showroom model. Meaning here that regardless whether it's sub zero with snow on the ground or it's scorching hot in the middle of summer, we want to be able to reach in through the door, turn the key and have the engine start and idle without needing to nurse it with the throttle for the first five minutes before you can start driving.

And this is something that I know a lot of tuners both amateur as well as professionals alike really struggle with. So today we're going to go through why we need cold start enrichment or cold start adjustments in the first place and then we're going to look at what's available in the Ecumaster EMU Black ECU and I'll give you some strategies that you can use to help adjust these. As usual we're going to be having questions and answers at the end so if there's anything I talk about today that you'd like me to explain in a bit more detail or any questions related to this topic, please ask them in the chat. So the first aspect is why do we need cold start enrichment? What's the point, why do we need that in order to get our engine to run properly. A lot of this really comes down to the way the fuel is injected and then makes its way into the cylinders.

When the engine is cold, the ports, the valves are all cold as well and what happens here is that when the fuel is injected, a lot more fuel on a cold engine is going to end up condensing out against he port walls. When this happens, that fuel doesn't enter the cylinders in an easily combustable form, might sound a little bit counter intuitive but liquid fuel doesn't actually burn that easily. What we need in order to combust really easily is we need finely atomised fuel or fuel vapour even better. And that's harder to get when the engine is cold. So what this requires is first of all, in order to meet our normal operating air/fuel ratio targets, we're going to need to inject more fuel than when the engine is hot.

At the same time, even if we are targeting our normal operating lambda targets or air/fuel ratio targets from when the engine's hot, you're going to find that generally the engine's going to perform a little bit better, maybe a little bit more smoothly if you target slightly richer when the engine is cold as well. Now on top of this the other aspect that we need to consider which goes hand in hand with our cold start tuning is that we're going to need an extra air bypass, we're going to need to actually introduce more air into the engine in order to make it idle properly and again just like a slightly richer target air/fuel ratio, generally we're going to want to step up our target idle speed when the engine is cold. So there's a few interactions here, there's a lot going on, there's a few moving parts and this also comes down to the process we're going to need to go through in order to tune each of these elements correctly. The problem here is that in order to tune our cold start effectively, we need to start with a completely tuned engine in all other aspects. This is because a lot of our cold start adjustments actually act as a multiplier or a correction factor over and above our normal volumetric efficiency table, fuel table values.

So what I'm getting at here is if you try get your cold start worked out first, and then you find that your VE table isn't correct and make adjustments, that's going to have a knock on effect of throwing out your cold start adjustments. The flipside of that is if you do it the other way around, you're going to find that if you are trying to get your cold start dialled in correctly, you might be baking in errors because your VE table isn't correct. This does add an element of complexity to tuning because understandably, when we're finished tuning the engine and we've got our VE table all dialled in nicely, the engine's no longer cold, it's going to be at operating temperature. And it's not like we can walk away and leave the car for an hour or so, have a coffee and go back and have at it. Really when we're doing cold start tuning, we need to make sure the engine is completely cold.

And this really requires overnight so back when I was running my old workshop tuning cars, we always had a two day window when we brought cars in for tuning. The first day the car would do on the dyno, we'd get the tune dialled in on the dyno, we'd road test, make sure everything was perfect out on the road and that just left the cold start and idle speed tuning which we would then do the next morning before returning the car to the customer. Another aspect that I'll just chuck in here as well that is a consideration, there's no easy way around this. If you live in an environment like we do here in Queenstown New Zealand where we see very different weather patterns from Summer to Winter, this adds another curveball. The problem here is that if you are tuning a car in the middle of summer here, cold temperatures in the morning might only get down to 12 or maybe 15°C.

So then we get into winter which we're in now and it's not uncommon to have sub zero temperatures in the morning, maybe -5, The problem is that there's no way of us being able to accurately tune the cold start parameters at -5 or -6 if we can't actually get down there. So what I'm saying is if we're tuning this car here in the middle of summer, we can do our best, we can extrapolate the trends we're seeing in the warm up enrichment, the idle speed duty cycle tables etc down into those lower areas but there's a better than average chance that it still might not work out to be perfect. So a quick way of dealing with this, if you're running a performance workshop and you're tuning for customers, this is how we dealt with it, we would simply explain the situation to the customer, if we happened to be tuning in summer and say, if you find that when the temperature's a little bit colder you're starting to see some problems creep in, let us know, bring the car back and we'll touch that up for you at no cost. That's a nice way of getting around that. Giving your customer an understanding of their expectations as well means that you're not going to end up getting a bad name because the car's no longer starting under conditions that you weren't able to tune for.

So just sets up the customer for what to expect from that car. Alright enough talking about the background here, let's talk about the considerations and really there are a few aspects that we need to deal with. We're going to probably, depending on the ECU, obviously we're dealing with Ecumaster here, we're probably going to have a cranking enrichment, so this is additional fuel that is supplied just during the cranking, while the engine is cranking over on the starter motor. From here we will then move into a post start or afterstart enrichment as Ecumaster call it. This is immediately after the engine transitions from cranking to running and usually, regardless whether it's hot or cold, some additional fuelling is going to be needed momentarily for a matter of a few seconds just to let everything stabilise and then we're going to move into a warm up enrichment map.

Warm up enrichment maps, generally going to be either 2D or 3D versus engine coolant temperature and maybe we'll chuck load in there as well. On top of that, as I've already mentioned, we're going to need to consider our idle speed control parameters and step those up accordingly. Last one in there as well is acceleration enrichment also needs some adjustment. During cold operation we're going to find that to get crisp acceleration or transient response we're going to generally need a little bit of additional fuel. I'm not going to be covering transient enrichment inside of this webinar but just understand that that is a consideration, we'll run another webinar on transient enrichment on its own, because it is a reasonably big topic.

Now there's one aspect I actually overlooked here, there is also a prime pulse option available in the EMU Black ECU. I'm not using it here on our version 11 STi, I haven't found a need. On different ECUs that I have used that also feature a prime pulse, this tends to be useful if you've got injectors that are fitted a long way from the intake ports, just introducing a first squirt or fuel injection pulse when, in this case with the Ecumaster ECU, as soon as synchronisation is reached. Alright so those are our main considerations but as I've mentioned, I just want to reiterate once more because it is so important, we need to make sure that our volumetric efficiency table is tuned correctly first. So let's just head across to our Ecumaster EMU Black software and we've got, we're on our fuel tab at the moment, we can set these up however we want.

I've got this set up with some basic parameters that I'm generally going to want to see so this is our VE table which is our first place to get started and we can also view this graphically as well. A little bit of ugliness and weirdness in around the 2500 to 3500 RPM range on the version 11 STi which is an aspect of some weirdness in their fuel system, so anyway that's what that all looks like. So on this basis, we've got that table dialled in where we'd want it. Unfortunately not going to really get a perfect representation of this because I have had to use the car today so we've got our coolant temperature sitting at 31°. And just to chuck us another curveball in here, just before our webinar, my intake air temperature sensor decided to go bad on me so that's defaulted to 25°C.

I can assure you it is much colder than that right now. We've also got, over here on the right hand side, our graph log and this is a really nice aspect of the Ecumaster software, allows us to log a variety of parameters while the engine's running and then we can come back and go through that log and see exactly where we were operating, obviously the engine's not running at the moment at that particular point, and see all of the data that was relevant at that particular time. So we can see while I'm over here with the cursor, over here on the graph, all of the numbers, I'll try and show you this, all of these numbers here, they're currently green 'cause I'm off to the left, these are live numbers. If I come over here, they're blue and they're showing the values at that particular point so really important to just understand that. Alright so assuming we've got our VE table tuned under normal operating conditions we then need to have a look through our available parameters.

So we're going to start with our engine start parameters which is over here in our menu structure, we'll bring that up here. And we'll just have a look at what we've got. So we could set up another page for our cold start, I'm just going to, for simplicity, bring these up over on top of our fuel tab. So we'll open up our engine start parameters, I'll just bring these up here so we can see them. So we've got the enable prime pulse which I've just talked about so I've actually got that ticked at the moment but as I mentioned, in most instances you're probably not going to find that that is essential.

And a lot of these elements, it is a bit of a trial and error here so we can find that you're just going to want to test some of these options and see if you get a better result. Generally I'd expect, starting with that disabled and then only enabling it if you really need it. You've got the option of also batch firing all of the injectors together. If they're running sequential, basically this will fire the injectors once per ignition cycle. Basically helping to introduce fuel quicker.

We've also got our cranking RPM threshold So important to have this set realistic. Basically we want to make sure that this is somewhere above the normal cranking RPM but below our idle speed. So 400 probably a pretty safe bet for most engines. We've got an engine stall rev limit so basically if the engine RPM goes below 60 RPM, that's going to disable fuel and spark. We can then also set our cranking ignition angle So this fixes the ignition timing at whatever value we've got.

Generally we're going to find that most engines will start pretty happily between maybe zero and 10°, 10° normally works pretty well for most engines. We can also disable the spark here with out start delay. So a function that we'll see in a second. So the spark delay, sorry start delay, we can basically delay the starting process, purposefully stop the ECU from starting the engine to allow the engine to build up oil pressure prior to our first start. Alright so that's our first set of parameters there and we'll move down here, we've got two cranking fuel tables, we're only working on cranking fuel one so again, let's bring this up so we can have a better look at is here.

So this particular table here obviously is used as its name suggests while the engine is cranking. So it's some initial fuel that is provided during cranking and you can see this is 3D table, we've got our coolant temperature on the horizontal axis and we've got the number of the engine revolutions here so we can see that we've got quite large values here in terms of pulse width down at cold temperatures and with our first engine revolution and then this gradually tapers off. So we do need to be a little bit careful here because the numbers for this table will depend on our injector size and it is also very easy to end up flooding the engine so it's a good idea with these to start with numbers that are small and then build up on that rather than starting with numbers that are too large and finding that we're actually flooding the engine. So what we're going to find here, we can't tune this table using a wideband air/fuel ratio meter because during the cranking process, we're not really going to be getting any combustion or stable combustion occurring so measuring the air/fuel ratio in the exhaust gas isn't going to be possible. So this needs to be done by trial and error.

What I generally do when I'm making a change to these tables initially is I make quite a big change so maybe somewhere in the region of 50% in a step. And this is going to be big enough that gives us an idea, did that make an improvement or did it make things worse. Once we sort of get a direction for our tuning in terms of that table, what we can then do is start fine tuning, making smaller changes and dialling that in. You'll also find here, this is true with most ECUs I deal with. I've actually got a little bit of a hole here which is a little bit odd.

But essentially what we'll find is that a lot of these tables, the numbers in them, the default values in them are probably going to be a pretty good place to get started and the other aspect here is the general shape of this table is probably what we're going to be wanting. So in terms of that, rather than saying alright we're starting here at 0° so let's see what our performance is like, What I'd tend to do is make a overall change to the entire table, so we can do that by highlighting the entire table and then we can make a percentage change so we can do this by entering, let's say we want to halve that table value, we can enter 0.5, we can then enter the multiplication symbol and that will halve all of the numbers. So this keeps the general trend or shape of the table, control Z as well, just a little shortcut there which is really nice, a lot of ECUs don't have, allows you undo your changes. So yeah allows you to dial in that table shape without having to do each zone individually. Generally what I would do as well with this, we're going to obviously be concentrating on our cold start performance.

So depending on your climate, that's probably going to be down somewhere in this region. Dial that in, get our whole table sorted out like I've just shown you and then we can obviously spend plenty of time checking the hot restart performance up in this area. You can see that the numbers we need are much smaller but basically if we find that manipulating the entire table means that our warm start enrichment is no longer, warm start cranking is no longer correct, what I would then do is concentrate just on the areas for hot start and we can then do some linear interpolation between the cold areas that we've dialled in and the hot areas. This just means that we don't have to test at every single break point in this table. And again the engine's only spending a few seconds in this area so it's just enough to get crisp startup of our engine.

So we've also got a scaling for our fuelling based on TPS, I'll bring that up here. So this just allows us to scale how much additional enrichment is provided based on our throttle position. So you can see here as we go through to full throttle, we actually taper that enrichment off. So there's more airflow at wide open throttle and this can be used sort of as an anti flooding aspect as well. Our prime pulse, if you want to use it, double click on that and bring that up and this is again millisecond based as well so important just to mention, so most ECUs I deal with tend to do their warmup corrections in terms of a percentage change.

For me that makes a little bit more sense, when we're dealing with millisecond based, we just need to be a little cautious because if we go a much bigger set of injectors, then we're going to need to affect these tables whereas often if they're percentage based they won't need changing or if they do, they're relatively small. Then we've also got our start delay as well which we are not using but allows you to delay the start for a number of revolutions, again I've sort of explained what that's for. So that's our base parameters there. Next we're going to move into our enrichments. Let's close that down.

And we've got a few options here, we've got after start, we've got acceleration and we've got warmup so as I've already mentioned, we're not going to touch on our acceleration enrichment here today. After start, pretty self explanatory, this is a enrichment that is used as the engine transitions from cranking to running so we've got our cranking enrichment, that's while the engine's cranking then that drops out and we move into our after start enrichment and then finally we move into warmup. So we'll have a look at our parameters for our after start here. And we've got our after start duration. Interestingly in cycles, nothing particularly wrong with that, we can easily work out using our log graph how that represents a time range as well.

We can also lock our ignition timing if we want to but no big deal there as far as I'm concerned. Then we've got our after start enrichment table so we'll bring this up. This one is percentage based here. Oops, bring that back up. Relative to our coolant temperature obviously.

So what we can see here is the, it's the enrichment is higher, we've got 35% down there up to about 40°C and then that drops down so we've still got some after start enrichment which can be helpful even with a hot engine, particularly when it's heat soaked to get the engine to start cleanly and seal into a nice idle. So the after start enrichment, we can start using our wideband to help us tuning that. There's a few interactions here though so it is important to understand what we can expect. So first of all, I've already explained that with our cranking enrichment we can't really use our wideband air/fuel ratio meter to help us too much with that. That's still true, it's still valid but what we will find is that once the engine does start up if we've got a lot of cranking enrichment that's going in there and we haven't actually managed to foul the plugs, what this is going to do is result in momentarily, once the engine does start and settles into an idle we're going to see our air/fuel ratio drop very rich.

So it can still be a hint there, this could be affected by too much cranking enrichment or we could have simply set our after start enrichment to be a little bit too aggressive so again just understanding what we're looking at there on the wideband and what that's representing. So the after start enrichment basically we want to tune that so that we've got crisp control of our air/fuel ratio immediately after startup and we'll be able to see in our logging how that drops out over time as well. Then we're going to move into our warmup enrichment so we'll have a look, again we've got two warmup enrichment tables here, just open this up a little bit so we can see that in a bit more detail. So we've got here a 3D table, we've got coolant temp on the horizontal axis which is probably pretty self explanatory and we've got load in terms of manifold pressure on our vertical axis. Doesn't necessarily have to be 3D like this, it's not essential but it can give you a little bit more control.

The reason for this is while, yes, when we've got the throttle closed or close to closed at low load, we're going to need more fuel enrichment to get our air/fuel ratio on target. What we do find is that if we don't have a lot of mechanical sympathy and we cold start the engine and go straight to wide open throttle, maybe one bar of boost, given the higher airflow this actually helps with the fuel atomisation, it forces the fuel into the cylinders and we tend to find that our required enrichment is nowhere near as great compared to it we're in vacuum so this allows us to taper that off which is exactly what you can see. If we're up at 200 kPa here we've got significantly less enrichment than what we've got when we are at 20 kPa. So that's our basic parameters there for our warmup enrichment. The other aspect as I've mentioned that goes hand in hand with this is our idle speed control.

So we'll just quickly head over to our idle speed control page. Couple of aspects, I'm not going to dwell on this part too much because this is really sort of a separate aspect but just worth understanding. First part here is our idle target table. So just making sure that we've got realistic idle targets. You can get a pretty good guide on what these should be from the OE manufacturer's target idle speeds.

We can see down here, particularly in cold start we're around about 1200 to 1250 RPM, we've got a linear interpolation down to 900 RPM at 70. Now the next aspect that goes hand in hand with that is our base idle speed reference which is down here. Idle reference table in Ecumaster lingo so we can see that table down here. We've got a 3D table, again coolant temp versus our idle target. So it's really important, before we do any closed loop, or add any closed loop control to make sure that we've gone through and made these targets as accurate as possible.

So we can see that when we are, let's say at 85°C here, we can see the variation in our idle target, sorry our idle duty cycle which actually in this case represents a drive by wire throttle opening. At 800 RPM we're targeting 10% of our available throttle opening, it's not actually throttle opening, it's a percentage of our idle throttle target, little bit complex, different topic for a different day but basically 10% through to 1600 RPM we're targeting 31% of that available opening. So really important to get this dialled in because it's going to make the rest of your job much easier. At this point, you're probably getting the idea that there's a lot of moving parts to this that all require adjustment so this can require a couple of attempts to get it really dialled in. It's going to depend on a big degree to how good or how close the default values are inside of the generic maps that you get with your ECU.

So often these will be pretty close and might only require a little bit of fine tuning in which case we're good to go. In other cases where we find that the first cold start is just a complete disaster and we're completely out of the ballpark, in that case it may take three or four attempts to actually get our cold start tuning dialled in. Once you're a little bit more confident with the process though, because obviously the engine does warm up relatively slowly, we'll find we're going to have the opportunity to switch back between our warmup enrichment tables and our idle speed target tables and get both dialled in kind of simultaneously so it's not as scary as it sounds but we do only really get one shot at that initial startup. Alright so now that we've got a bit of an understanding of what we're doing, I'm going to come back over to our fuel tab here and I'm going to bring up our warmup enrichment table here. And we'll just get rid of the graph 'cause we probably don't need that for our purposes.

So we can see at the moment we're sitting at 30° and obviously 100 kPa give or take so 110% in there, 10% more enrichment. So again not really going to get a fair crack at this because our engine isn't truely cold but let's just get our logger running here. I'll actually power the car up which might help with that. And we will just do a startup here and we'll just have a look at what's going on. So one of the things that we want to watch here, we've got our lambda versus our target as well so this is going to be one of the key aspects that we're watching during the warmup process so we want to watch our air/fuel ratio, see how well controlled that is and we're also going to be watching our engine RPM and makes sure that that is sitting on our target so hopefully this demonstration doesn't turn me into a liar here, let's see how well this all works out.

OK engine started which is great. Straight away we can see our lambda on our target there. Generally I'd say that's probably a little bit lean though for cold start. We'll have a look at that in a second. Our RPM also flared up to about 1400 before settling down to 1100, that's our initial startup.

We can see our lambda's still on track there. But we're probably a little bit lean so what we can do here is we can just add a couple of values in here and we'll see that our air/fuel ratio does track a little bit richer, right onto our target. Let's just pause our graph here and we'll have a quick look at what happens. So in particular here, we've got our after start enrichment being shown. So we start here with 100%, we crank the engine and we see that our after start enrichment jumps up to 35% and we can see the shape of this as it tracks back down to zero so remember we had that set for 100 engine cycles.

So depending on what our air/fuel ratio does immediately after startup, we can manipulate that, make it longer or shorter. We'll just have a look at what's happening live here. We can see that we're a little bit rich here so in this case, again assuming that our VE table is dialled in, we're going to make these adjustments here in the actual warmup enrichment table so we can use alt and minus here just to remove a few percent out. Now I' not actually too worried about being a little bit richer than our target there while we're still warming up, we're only at 40° there so we're just watching what everything's doing here, our target idle speed's tracking quite nicely so I haven't needed to make any changes to our idle speed but of course if we did, we'd swap back across to our idle tab and we can make those changes straight in there. So of course at this stage, I've got a relatively well developed calibration for this particular engine so no big surprises, not a huge amount of work needed to do.

But the elements that we want to consider, first of all, that cranking enrichment, looking there primarily, are we getting crisp startup. Then our after start enrichment, do we see a massive lean dip or rich dip straight after startup and then how well is that transitioning into our warmup enrichment table? We'll move into questions in just a second so this is a good opportunity to remind you if you've got any questions, please ask those now. Now just again to reiterate that process here and what you need to keep in mind, the other aspect is making sure for your cold start operation that your wideband is actually coming up to operating temperature straight away, we don't want a wideband that doesn't read for the first 30 or 40 seconds of engine operation during a cold start which is what we do find with a lot of wideband controllers, they do this to protect the sensor and extend sensor life. Unfortunately when we are doing cold start, we do need that sensor online straight away so that's one important aspect. In our case we're bringing that wideband information in via a external CAN based wideband controller, if you are using the internal onboard wideband in the Ecumaster EMU Black, you do have the opportunity to select fast heat which can shorten sensor life but brings it online a little bit quicker.

If you don't have that, obviously you are completely blind. And again just to also remember that you're going to need to make sure that the engine is completely cold before you actually start. You'd be quite surprised just how long residual heat is actually held in the engine block and you might think that the car and the engine are completely stone cold but yeah they've still actually got a bit of temperature. And even if you're only five to 10° above the ambient temperature when you try and do your cold starting, it's not really going to give you a true guide to what you need to do. Alright we'll have a look at our questions, and again if you've got more, please keep them coming.

And we've got none, which obviously means I've done an excellent job of explaining all there is to know about cold start enrichment. Oh I speak too soon, Michael's asked, have some questions regarding cold start at high altitude around 1000 m above sea level with the temperature between 16 to 20 degrees on an SR20DET, please advise? OK so the question I've got here is are you seeing a consistent altitude of 1000 m or are you moving between sea level and 1000 m? If you're at 1000 m, I really don't see that that's going to be, consistently at 1000 m, I don't really see that that's going to be a huge concern for you, obviously you're at a consistent operating altitude so that's not going to play a big impact on things. In terms of the cold start operation though, while barometric air pressure, which is affected by your altitude is going to affect elements of your tune, that's not necessarily something we're going to want to factor in solely to our cold start performance. In most instances, and 1000 m I don't think should give you too much reason for concern there, most people don't even bother with adding baro compensation in. The alternative though if you do want to learn more about that, we've got another webinar in our archive you can check out which covers tuning for altitude changes.

3lbtrigger​'s asked, would it then be beneficial to let the sensor warm up for 30sec before starting? Yes and no, it depends on your controller so if you've got a controller that is pretty smart, then often these controllers will actually require an engine RPM signal before they'll start the heating process. So this prevents this sensor from being heated and then shocked by condensation, moisture in the exhaust during a cold start. So it's a bit of a catch 22 unfortunately. Of course if you've got a third party wideband that doesn't have the functionality then yes by all means, get it set up and operating before you start. One thing that is a consideration here again depending on your wideband, I use the Innovate product quite a lot and if you are powering that from the accessory jack, so if you've got a portable, like an LM2 not a fully wired one, then what you'll find is that yes you can power the car up, it'll bring the sensor online and you'll start getting a reading and then as soon as you crank the engine to start it of course that interrupts the accessory power, it drops back out and it's still going to take 20 or 30 seconds to come online once the engine starts.

In that aspect, it's a good idea to temporarily just hard wire to your battery so it's going to run the whole time. Khelan has asked, ​what is the name of the tuning software? It's the Ecumaster Black, or Ecumaster EMU Black software so it's specific for that particular ECU. Oper8or's asked, I'm completely new to tuning, are there any simulation applications for tuning? Unfortunately not that I am aware of. If anyone does know of one, I'd be pretty interested to hear about it but yeah not that I'm aware of. My suggestion, if you are completely new to tuning, first of all, you're in the right place, I would suggest getting yourself a relatively cheap car with a naturally aspirated engine because these are going to be pretty difficult to break or damage while you're getting started and learning and then apply our lessons and that will teach you everything you need to know.

Dillon has asked, ​is it possible to get stock like starting on pure e85 or m1? It depends. The problem with E85 or methanol for that matter is that it has a, it's not as volatile, that's the word I'm looking for. Doesn't have the volatility of petrol so this isn't normally a problem at higher ambient temperatures but at lower ambient temperatures it can be an issue so depending, my own experience, probably down to about 5°C engine coolant temperature and air temperature, I can get pretty muck stock like starting performance on full E85, methanol's a different story but probably not going to be running that in your daily driven street car so less of an issue. Once we get down below about 5°C it is going to get progressively more difficult, some engines will start easier than others but it can be problematic. This is one of the reasons why we see that the specification for pump E85 actually allows it to go down to I think it's about as low as 61 or 62%, might want to fact check that but basically in winter blends of E85 in colder parts of the world, they will actually reduce the ethanol content to improve the volatility of the fuel and allow easier cold starting.

Alright we will leave it there, thanks for watching, thanks for your questions and remember if you are watching this in our archive once it's aired live, if you've got any further questions, please ask them in the forum and I'll be happy to answer them there. Thanks for joining us, hopefully we'll see you again next week.