Don't use 87 octane (C)

[II kings 9:20]

I thought I'd give 87 a whirl, save a dime a gallon . Comming up my big hill today it began to ping!!! Last time for this boneheaded maneuver. My X5 required 93 and I used 87 all the time with no issues at all which is why I was willing to try 2 points lower in the C, boy was I wrong.

[IceMan1959]

Originally Posted by II kings 9:20

I thought I'd give 87 a whirl, save a dime a gallon . Comming up my big hill today it began to ping!!! Last time for this boneheaded maneuver. My X5 required 93 and I used 87 all the time with no issues at all which is why I was willing to try 2 points lower in the C, boy was I wrong.

Humm I was 87 about 1/2 the time I have always had good luck with it and could not tell of any power loss or MPG loss.

[NickDavid]

damn, thanks for posting that! With the gas prices going up so much, I was gonna try that and see how it performed. I always run 89 octane or the middle grade. car runs perfect with that.

[jjs]

Originally Posted by IceMan1959

Humm I was 87 about 1/2 the time I have always had good luck with it and could not tell of any power loss or MPG loss.

He was referring to detonation (not a good thing at all for an engine), not any kind of loss.

[IceMan1959]

Originally Posted by jjs

He was referring to detonation (not a good thing at all for an engine), not any kind of loss.

going to have to find me a nice big hill. Time for a trip to Mena Ark. that should do it.

[marlinspike]

Kings, if you're pinging, I would definitley not let this tank run it's course. Get 93 in there as soon as there is space to try to balance it out. If there is a way to do it on these cars (I don't know much about these fancy pantsy cars and their com-pu-ters) you might want to set the mixture rich.
Richard

[Mopar Crazy]

I thought I had read somewhere on these forums that 87 was just fine, and that there were no adverse affects. I have used 87 the entire 3400 miles, and she runs great. I did read in the oweners manual that 89 is recommended, but 87 will work fine. It said that premium was NOT recommended, which suprised me.

[baj764]

I have used 87 about 40% of the time in my 3 months and 2500 miles. It has worked fine. Wonder if it could be something else or maybe just a bad tank of gas.

[magnuman]

DCX knows what they're doing. That's why they chose an octane that will work for all. With all the variables involved with vehicle octane requirements, 89 is the safe, and conservative compromise for all. This is not to say that lower octanes can't, or should not be used. That is why they use the terminology, "recommended". Those that live in cooler climates may be able to use a lower octane fuel in the winter. (See last reference). Owners that live at altitude do not need, nor require the higher octane (a waste of money), as stated in the following references:
Gasoline Digest, "In high-altitude areas, you’ll find lower octane gas. “Pressure and temperature in the combustion chamber are less at altitude.” Wusz stated.

Gasoline FAQ, "On modern engines with sophisticated engine management systems, the engine can operate efficiently on fuels of a wider range of octane rating, but there remains an optimum octane for the engine under specific driving conditions."
"Once you have identified the fuel that keeps the engine at optimum settings,
there is no advantage in moving to an even higher octane fuel. The manufacturer's recommendation is conservative, so you may be able to carefully reduce the fuel octane."
"If you are already using the proper octane fuel, you will not obtain more
power from higher octane fuels. The engine will be already operating at
optimum settings, and a higher octane should have no effect on the management
system. Your driveability and fuel economy will remain the same. The higher
octane fuel costs more, so you are just throwing money away."
"You may be able to change octanes between seasons ( reduce
octane in winter ) to obtain the most cost-effective fuel without loss of
driveability."
So, not everyone needs, nor should necessarily use 89 octane fuel. As stated in the references, find the one that works best for you, in your environment and climate, and go with it. Some may be able to change octanes from summer to winter. Personally, I've used 87 almost since I got my Magnum RT, and although the per tank savings is not that much, figure the savings over 15000-30000 miles at today's prices, and the savings are no longer pennys. Using 91 or 93 anywhere would definitely be a waste of money. Also, those who must use reformulated or oxygenated fuels will probably see lower performance and lower mileage.

[phunter1]

Hi,

I live on a hill, just over 150 ft above sea level. I have been using 87 octane for the last couple of months. I have not had any pinging, nor have I noticed any power or fuel economy loss.
I would suspect bad gas as the culprit. I had a situation a few years back with my 1998 T&C. I filled up in Orange County and returned home over the Ortega Hwy, which is a winding mountain road. On the way home, the van started pinging and over heating. When I got home i drained and flushed the radiator, but it was very clean. The problems continued until I got down to about 1/2 tank, when I added 91 octane to fill the tank. The pinging and overheating immediately went away. I never had the problem again, even with 87 octane, so I believe I got a bath of bad gas. This may have been the problem.


Phil