octane rating and engine performance
In Texas, the minimum octane rating is 87. On a recent trip to Glacier, I noticed a lot of the fuel in states like CO, WY and MT, the octane was 85, and you had to buy the mid-grade to get 87 and abov...
Forum Discussion
He is also purposely leaving out a very important part of that 91 octane recommendation. It specifically states.
"For best overall vehicle and engine
performance, premium fuel with an octane
rating of 91 or higher is recommended."
Meaning that if you want/need the added 5% or so of horsepower output which is the best performance of that engine, then 91 or higher is recommended. Many Ford engines have different horsepower output numbers depending on the octane used.
My wife's N/A 3.5L Infiniti is the same way it is about 310 hp on 91 octane and around 290 hp on regular. However, the recommendation is reverse for her car. It states that 91 is recommended, but can run on lower octane with less performance.
"For best overall vehicle and engine
performance, premium fuel with an octane
rating of 91 or higher is recommended."
Meaning that if you want/need the added 5% or so of horsepower output which is the best performance of that engine, then 91 or higher is recommended. Many Ford engines have different horsepower output numbers depending on the octane used.
My wife's N/A 3.5L Infiniti is the same way it is about 310 hp on 91 octane and around 290 hp on regular. However, the recommendation is reverse for her car. It states that 91 is recommended, but can run on lower octane with less performance.
