What gasoline do you use?
 

What gasoline do you use for your Mustangs? For Mustangs equipped with the 5.0L V8 Coyote Engine, I was told that regular gas is fine for it. Yet some claim that I should be putting the 91 grade gas since the regular gas will gunk up the engine.

Thanks for sharing,
Jonathan

Go with the owners manual recommendation, if the engine isn't tuned for 91 octane, theres no harm, but you're wasting money.

Regular gas will not gunk up the engine......diesel fuel might, but not regular gas. lol

If you go with mods that need a new tune, you might upgrade to 91, but stick with good old regular as your owners manual will say, probably 87 ???

Check the inside of your fuel door, my car is tuned for minimum 91, I can't run regular, it may not gunk up the engine, but it won't run right....

https://cimg6.ibsrv.net/gimg/www.cmo...aca78121a7.jpg

I use 91 in my 4.6. It gets better mileage with it and as with the 5.0 it will get slightly better power with the higher octane I'm pretty sure.

Ultra 94 for me. I also will put 93 in from the Esso near my place. Luckily both are near me.

93 is my choice as well, probably wasting cash over 91, but its my preference, I could care less about mileage. lol