I regularly fill up with 90 octane 10%ethanol in my 4.0sohc

i love mohawk and husky gas stations here in canada. their regular gas is 90 octane and its the same price as all the other stations 87 octane fuel

I did a test with that fuel vs 87 octane. I get an extra 25kilometers from using it on a full tank. and i go through about 2 tanks a month, the savings add up.

 

I've done a fair amount of testing timing and different octanes in my 06 FX4. (differing tunes too) The stock tune just does'nt have enough timing to get into the knock sensor on 87 octane. So on a stock tune the only thing you'll gain by the more expesive gas are the added cleaners. But.. there is always gas that do and don't have 10% ethanol. That effects mileage as well.

btw 1, I have a friend who's high up at Marathon. He told me that the only difference (at thier company) between 87 and 89 is the octane. But thier high end "premium" 92 or 93 octanes have twice the cleaners in it as well as the added octane. The base fuel is the same. The additives are marathon specific depending on region and markets.

btw 2, on my 06 I've got the timing raised quite a bit and run 93 or 94 octane fuels. With my timing set as is (maxing at 26-27 at 4000+ rpms) I can get into spark sensor activity on 92 octane.

Rich

 

87

 

89

 

87...

It didn't make any difference what octane I ran in the ranger, and it doesn't make any difference what I run in the Jeep. Now, the brand of fuel I have noticed makes a pretty big difference. So far, my best results have been with Amoco (not BP, actual Amoco fuel) and Shell...

 

87

I normally get my fuel from one place. seems to run pretty good.

 

A stock motor with no modified tuning should be running 87. Nothing more, nothing less. You are not gaining anything from using a different octane. You are in fact losing.

 

Unless it a higher end car that the factory requires higher octane


I run 93 with a tune

 

Well.. that's not to say you'll loose mileage. Your just putting more money into the same miles traveled from a octane only perspective.

If the higher octane fuel has better cleaners and less alchahol in it. Then you'd see better mileage. Especially if the motor has high mileage on it.

Rich

 

Normally ethanol is used to boost octane, so your MPG should drop with the higher octane.

 

Not in all cases, some summer grades of gas here in Michigan do not use any ethanol at all...

 

87, normally I use Amoco fuels, sometimes I don't have a choice but to use the cheapest tho lol.

 

yeah I just run 87 from wherever I can find it the cheapest...

 

You'll probably lose mileage too. Octane retards combustion and that will not sit well in a stock ranger motor. You'll lose mileage eventually and probably build up a lot of carbon crud in your engine.

 

I agree 100%.

It's not like the good old days of the carbed engines. My 85 Cutlass ran much better with the high test. The Ranger, no difference.

I'll stick with the cheap 87. It's too expensive to run the better stuff anyway.

 

interesting.. not sure why im gaining mileage by using a high octane.. maybe its because its an 08

 

How are you determining your mileage gain?

 

It's probably not the octane. More likely it's a better base fuel.

btw, a higher octane fuel does not have a slower burn rate... hurting MPG. It simply resists detonation better.

Rich

 

I switch a bit..

run 2 or 3 tanks of regular 87.. then I'll fill up with some 92 and a load of injector cleaner... Keeps the engine running top shape, and builds up any buildup that happens in it.

Not sur eon the mileage, as its been off and on winter out here an dhas only recently gotten better, so clicking that 4x4 **** around sure makes a difference in MPG (I only got 130mpg on a 3/4 tank last time I was in 4x4 most of the day unloading that big 52 footer for work.)

 

How do you think it resists detonation? By not igniting and burning as fast.

 

87 I ususally run Shell or Chevron

 

Your simply wrong. Octane is a resistance to combustion.

http://en.wikipedia.org/wiki/Octane_rating (scroll down to "Effects of octane rating)

Here is a quote:
"Octane rating has no direct impact on the deflagration (burn) of the air/fuel mixture in the combustion chamber. Other properties of gasoline and engine design account for the manner at which deflagration takes place. In other words, the flame speed of a normally ignited mixture is not directly connected to octane rating. Deflagration is the type of combustion that constitutes the normal burn. Detonation is a different type of combustion and this is to be avoided in spark ignited gasoline engines. Octane rating is a measure of detonation resistance, not deflagration characteristics.

It might seem odd that fuels with higher octane ratings explode less easily, yet are popularly thought of as more powerful. The misunderstanding is caused by confusing the ability of the fuel to resist compression detonation as opposed to the ability of the fuel to burn (combustion)."

 

Thats what I've been saying all along.

 

87octane and ill fill up where ever, except for those po dunk EL GAS STATION with a taqueria inside of them

 

You mean every gas station in Houston?