Community Forums

KC1BUD · 08-12-2009, 10:32 PM

Quote:

Originally Posted by Homer

Unless you can't get 87 what would be the advantage of running 85. I live in the Midwest and have never seen 85 octane fuel, with the exception of Sunoco.

Personally I think that Sunoco uses the 85 octane to make them look cheaper, once at the pump most people will pump the higher priced 87 octane.

KC1BUD · 08-12-2009, 10:34 PM

Even my lawn mowers call for 87 octane.

Crankarm · 08-18-2009, 08:29 AM

Quote:

Originally Posted by Forest Grump

Since octane is measured in a knock engine by altering the engines compression it would suggest that if the 85 octane is not knocking then it's use is fine. However if it knocks don't use it.

we have a 2007 Winny Vista 30B on the Ford chasis with the V10. Have always used the 85 octane that is sold here in NM as "regular" This past weekend on a trip from ABQ NM to Leadville CO pulling our CRV...(all high altitude) I decided to try mid grade gas...87 octane. I have to say that the engine ran quiter...i am guessing that means less knocking. From now on, I will be using the mid grade...sure it is a dime more a gallon, but i think i proved to myself that it does make a difference in our motorhome

Izzyblueye · 08-18-2009, 08:47 AM

Quote:

Originally Posted by Crankarm

we have a 2007 Winny Vista 30B on the Ford chasis with the V10. Have always used the 85 octane that is sold here in NM as "regular" This past weekend on a trip from ABQ NM to Leadville CO pulling our CRV...(all high altitude) I decided to try mid grade gas...87 octane. I have to say that the engine ran quiter...i am guessing that means less knocking. From now on, I will be using the mid grade...sure it is a dime more a gallon, but i think i proved to myself that it does make a difference in our motorhome

I think you made the right decision. I doubt if most motor home drivers can identify a spark knock from many other sounds of an engine. By the time you figure out what it is the damage is done.

clevinberg · 08-19-2009, 05:47 PM

I used 85 octane in my Monarch 2008 in the midwest (north and south) with no problem. It is the altitude that they reduce the rating.

DriVer · 08-20-2009, 10:30 AM

I could be wrong here but if you look in your owner's manual ... does it not say the minimum Octaine requirement for your vehicle's V-10 is 87 or better?

Personally I would not run 85 Octaine even if it were 50% less money than 87.

When I ran out west, I bought 88 Octaine gasoline or better. Seems like they don't have 87 out there at all.

Have a good one ....

Doggy Daddy · 08-20-2009, 10:50 AM

I carry Octane Booster along just in case my RV or harley need some TLC.

Ethanol cost more, robs my engine of power and mpg.

dirko · 08-23-2009, 06:57 PM

Hi Ho: We tow a 2000 Saturn which interestingly enough requires premium (or at least something higher than 87 octance to prevent detonation). My hearing is non-existant above 3500 Hz and I could not hear the pinging, but my friends shure could.

The 2000 Itasca on the other hand doesn't seem to be botherd with lower octane. Modern engines can compensate the timing and if everything works normally only a power loss occurs.

Dirk

AndyG · 09-11-2009, 10:59 AM

The stuff that you were seeing in the midwest was probably not 85 octane gas. What we have around here (S.W. Indiana) is E85 which means that it is up to 85% ethyl alcohol and actually has a higher octane value than regular gasoline. E85 - Wikipedia, the free encyclopedia You do need to make sure that the components of your fule system are compatible with alcohol before using E85 though.

John Mo · 09-11-2009, 11:40 AM

It was 85 octane gasoline. I am familiar with E85 and it is specifically noted on my 2008 F53 that it can not be used.

TroutScout · 09-26-2009, 10:52 AM

85 octane was developed for high altitude use because it burns slower. You want it to burn slower because there is less oxygen available at higher altitude. The 85 octane "evens" out the combustion, fuel + oxygen ratio, which equals lower atitude ratio. At lower elevation 87 octane is used, it burns faster and mixes with the more readily abundant oxygen.

Crankarm · 09-28-2009, 09:39 AM

I just can't get passed the one line in the Ford manual that basically says they don't recomend using the "less than 87 common in high altitude states" There must be a reason for it

billyb · 09-29-2009, 04:17 AM

when we were out west, i ran 85 oc in our old 454 vortec and we seemed to get better mileage then on 87 oc. we ran several tanks of it and i still don't know what to think about it.

BigRedLancer · 10-01-2009, 06:30 PM

During our trip in May, I ran 85 octane in the MH and toad. I purchased the fuel in northern Arizona and southern Utah. The MH got a full 1 mpg better mileage, and the toad got 3 mpg better with the 85 over the usual 87 I use at lower altitudes. Couldn't hear a ping in either engine and the power seemed to be normal. At one station they didn't even have 87 available.