I would like to know just what octane of Gasoline to use in my truck. I have had friends tell me that I should use mid-grade (the low grade here in Great Falls is 85.5). However, I have had other friends tell me that I could use octane boost added to the aforementioned octane and get the same performance. I would like some help on this.


Thank you

 

I would use 87 or higher. Check the parts stores for information on octane booster.

I used to live in Great Falls, I left for Florida in '96. Check with Dave at Champion Auto on 10th Ave. Tell him Greg Casteel said Hi.

 

87 or whatever the owners manual says

85 octaine...interesting

no such thing like that around here

...zap!

 

Above 5000 feet 87 octane is a waste!

 

go with the lowest octane available.....your manual will give you the minimum you can safely run.....buying a higher octane is just a waste of your money...unless you got a tuner or a supercharger or something....higher octane fuel isnt going to make your truck perform any better....in fact buying 91 over 87 or 85 might actually hinder the motors performance because it takes more compression to ignite a higher octane fuel.

 

Higher altitudes permit a lowering of octane rating due to lower atmospheric pressure and lower oxygen concentration. At altitude, 85 octane will yield comparable performance to 87 at lower altitudes.

That said, you can expect diminished performance of almost any vehicle at altitude compared to sea level.

Steve

 

I use 89 oct. around here, because it's a nickel a gallon cheaper!!! This is also a 10% ethnaol blend.

 

Thank you for your input. I planned on using 88 in my truck. I find that I am getting better performance from the 91, however, if I can get as good of performance out of 88, I will use that.

 

I live in Denver, CO. So your saying 85 octane ( the lowest in Colorado is fine? ) comparable to 87 at sea level

 

Yup

 

manual says 89 and not to use anything higher.
About a year ago I remember AAA came out with a finding that stated you will get NO added performance usung a higher octane of gas than recommended by the manufacturer.

 

With no mods, regular gas is all you need. I have installed a Superchips program in my truck whick requires premium fuel, 91-92 octane. It pings without it. Gas prices have soared here. Premium is $1.32 CDN per litre.
There are 3.8 litres per US gallon, or 4.55 per Imperial gallon. It's a rediculous price but we pull into the station and fill up anyways.

 

87octane min is what is required by ford

 

Since I was both bored and curious, mainly bored, I took a look at my manual. Ford recommends 87 octane. They specifically state that they do NOT recommend the use of gas with octane ratings of 86 or less sold as "regular" in high altitude areas. Science says it's OK, Ford says they don't want you to. I guess the choice is yours...
This is from a 2003 owners manual.

 

I also found that in my manual and that was from 1997. I use anything above 85.5 now.