The octane rating is the average of the Research Octane Number (RON) and the Motor Octane Number (MON). Iso-octane has a rating of 100 and normal heptane has a rating of 0 so premium at 91 is equivalent to 91% iso-octane and 9% heptane in terms of energy.
Is there any difference in MPG when you use 91 vs 87 gas?
Is there any difference in MPG when you use 91 vs 87 gas?
I'm currently only using the 87 octane at the gas station for obvious reasons. The gas price is here in the SF Bay area around $2.51 although I got gas last week for $2.41 at Costo. I get roughly 52 MPG with freeway miles. Not bad.
Has anyone checked out to see if there's a difference between the 87 and 91 octane or perhaps the 89.
Thanks for replying. Happy Prius driving
I'm currently only using the 87 octane at the gas station for obvious reasons. The gas price is here in the SF Bay area around $2.51 although I got gas last week for $2.41 at Costo. I get roughly 52 MPG with freeway miles. Not bad.
Has anyone checked out to see if there's a difference between the 87 and 91 octane or perhaps the 89.
Thanks for replying. Happy Prius driving
