since we drive old sports cars (70's) what kind of fuel do you run with your 914, and do you ad any thing with the gas (additives)

from what I understand, most additives dont do anything. But in either case, I don't use them.

as for gas, I typically run 91 octane. The type 4 should run on regular, but I've always had better results with the extra "kick" in the octane.

not trying to hi-jack, but do you go to Cal Poly Pomona?

I always run 91 octane premium. I don't really have any scientific reasoning to back it up.

*runs and hides*

NO I have a studio in San Dimas

oh, ok. I might transfer from Cal Poly SLO to Pomona, so thats why I asked.

anyways

I haven't had any issues with Mobile and there 89 octane, works great. I wouldn't run anything lower than that though, some places sell 87 which won't go in the car.

50/50 mix of 110 leaded and 91 spreme or sometimes just 110.

93 here...though I have been told to use race gas.....where aside from a track do you get race gas? I wonder if I could use 100LL avgas?

Unless you are running a modified engine with high compression or turbo you do not need anything higher than 87 octane. The stock engines were designed to run on regular 87 octane fuel. But if it makes you feel better go ahead and run the higher octane, personally I won't be wasting my money on it and my car runs just fine.

I run 87 unless I am going autocrossing then I run the 91. I feel that why chance it with 87 when autocrossing. Hell, I am so slow I need every bit of help I can get.

There are a lot of common misconceptions about octane ratings. Here are a few facts about gasoline from the Minnesota dept. of commerce.

High octane gasoline burns slower than low octane gasoline. The slow burn prevents engine knock when cylinder pressures are high.
•If your engine runs well and does not knock or ping on low octane gasoline, there is no advantage in switching to higher octane gasoline.

Food for thought...

Google for race gas, there are a number of stations that carry it. I know of a couple here in the South SF Bay Area. That's in addition to the filling station at most tracks, of course. (Even more $$$ there, though.)

Don't use 100LL. It's only "low lead" when compared to older avgas; it still has enough to foul your plugs relatively easy.

--DD

I use whatever 87 octance is cheapest when I need to fill-up.

The funny thing is that I have friend who won't put non top-tier brand gas in their cars, and the only time I've had trouble was a day over the summer when I got diluted gas from a Mobile near where I work. When I drained the tank there was a ton of water at the bottom of the bucket. Needless to say I poured it back in leaving the water in the bucket.

Do a search on "Octane". The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine (pre-ignition).

The high Octane gas is primarily for high compression engines, and is used to ensure the fuel doesn't fire too early (pre-ignition). With our low compresion engines, there should be no need to use a higher Octane fuel. If your engine isn't pre-ignighting (knocking), then the higher Octane gas is probably just a waste.

I use "regular" 87 Octane gas on my stock '74 2.0L and it runs just fine

Eric Read

Run the lowest octane you can without pre-ignition (pinging). Running high octane for no good reason only results in carbon build up in the combustion chamber.

Yup not very smart to run 87 normally and then 91 for autocross.
Youare losing power with the higher octane.

I used the cheapest regular in 1973, and I use the same now....all my cars were fine with it, except the 2.7 twin plug....

By the way, bought a tankful of 87 octane yesterday for..... $1.79 per gallon!!!

can i just add 87 after i pimp 91?I have a 1/4 of the 91 in the tank?

Sure, you can mix them.

--DD