... good point. I filled at a Shell station both times, before going on the trip and then before returning from the trip. You might guess that most of my driving was on the highway.
I was going to try the same experiment on a long trip to see if any difference occurred. Maybe I'll fill with 94 octane and then try 91 octane to see the difference if any, we use a different method of measuring octane in N.A. reads about 5 point lower. Hmmm maybe I will try it anyway to see if any difference with a turbo.
It's to bad we can't find someone with access to a dyno.
In my SAAB owners manual it states that lower octane fuel can be used but engine power will be lowered. It also says that using lower octane fuel will give better gas mileage and on my car it does give about 1L/100Km better economy but I still use higher octane just in case of possible damage.
Have you noticed any 'pinking' problems using the lower octane fuel ?
On my SAAB I have never noticed any pinging/knocking under heavy load regardless of octane. I have heard pinging occasionally in the B, usually when it has not been on the highway for awhile.
The gas filler does have a octane rating of min 93 so it should run on 89 octane N.A. or mid grade.
Ah different terminology again I assume your pinging is our pinking the tinny rattly noise (hard to describe it but obvious when you hear it) coming from the top part of the engine on using either low octane fuel, excessivly weak mixture or incorrect timing.
The sound of ball bearings going down a metal drain pipe is the way I heard it described. Carbon in the combustion chamber also causes the same problem.
We used to time our engines by advancing the timing until the engine pinged just slightly, gained a little more performance. Of course a little to much advance and you ended up with holes in your pistons
I''ve used low octane for one reason or another often in my 300E and the B200, and have 'never' heard any preignition (or whatever you'd like to call it) - I do know what it sounds like from elsewhere. However, I also take care 'not' to accelerate hard
We've certainly have often discussed this octane question many times and it's seen in many MB forums.
From what I've read on all of these forums, "it's imperative to use the recommended octane for proper operation and longevity of your motor"
Trying to save a buck here and there in not wise and forcing the computer to compensate is not good in the long run in MHO, especially if you're forcing or in a hilly area.(Rockies)
The manual spells it out and it's not because MB own oil shares.
What would our technical expert Mike say?
Derek
Linear Mode
