regular are premium feul

[jazz_master221]

is it wise to use 91 octane premium in my 97 ford explorer sport with a v 6 4.01 engine

 

[Jason_25]

No.

It is wise to follow what is recommended for the vehicle: Good 'ole 87 octane.

 

[B94Sport]

Using 91 octane won't hurt your truck, only your wallet. You gas mileage will most likely be worse if you use a higher octane without engine mods that take advantage of it, such as a chip.

 

[Alec]

Welcome!

Yup, use regular gas. If you have knocking with regular gas, midgrade is ok. But no reason to use premium if you don't have computer (or serious power) mods. If you have knocking with midgrade, there's something wrong.

 

[pctorque]

Higher than recommended octane gas could cause:
-Shortened plug life
-Cat failure
-Shortened O2 sensor life.

Because the higher octane could leave unburnt fuel to pass through... or fuel as it's burning to pass through the exhaust

Using lower than recommend octane causes detonation and shorter life of most everything

So sticking with what's recommended is best. Though some cars do well for adjusting engine management for different octane, most get best gas mileage and component life if using what they say. That is considering you're running stock.

 

[jazz_master221]

thanks guys i'll start using 87 octane ...maybe that will help my gas mileage ...

 

[jonny 5]

Hey, another person from MA! Nice to see ya!