Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Mobil 98 - Pump gas or Iso-Octane?

EFI Tuning Fundamentals

Forum Posts



Tech Articles

Discussion and questions related to the course EFI Tuning Fundamentals

= Resolved threads


Is 98 octane fuel from Mobil classed as pump gas on the 'Stoichiometric air-to-fuel ratios of common fuels' or something else?

Edit: What's the Stoichiometric ratio for Mobil's 98 octane that would result in theoretical perfect combustion.

Attached Files
  • Stoichiometric-air-to-fuel-ratios-of-common-fuels-Sheet1-3.pdf
  • Attachments may only be downloaded by paid Gold members. Read more about becoming a Gold member here.

Hi Hayden,

With fuels the stoichiometric number changes from fuel to fuel, brand to brand and even batch to batch.

Oem manufacturers will test across all varieties of blends where this number changes; the 14.7 is taken as the general number for a gasoline/petrol fuel.

Producers of the fuels will have data sheets available for their products, I have had a very quick scan to see if I can find one in the public domain for the Mobil fuels but with no luck.

From memory of previous oem fuel testing some 98ron blends can vary from 14.2-14.8, but again 14.7 is widely considered to be the reference number to use.

I hope this helps and if I can find a data sheet I will post it up!

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?