Dear Porsche lovers!

I have an early 944 (1985) automatic transmission. I have no idea what octane of gas the previous owner was filling it up with, but the people I know and even the gasstation ownerssuggestedto me to use at least 98 octane unleaded gasoline. And ever since, I use100 octane unleaded gasoline, V-Power from Shell.

http://en.wikipedia.org/wiki/V-Power

I really don't know or can understandif any performance differences occur when I use a 95 octane unleaded gasoline rather then 100 octane, and I wonder whether my car would work better with leaded gasoline (because it's an old car, and the unleaded gasoline technology wasn't that advanced then) and if so, what octane should I use.

I'm not curious about the gasoline prices or aftermoney, I just would like to know what is best for my car and its engine.

Thank you all!

Regards,

porsche_lover

 

If you are in the US, you only need 87 octane in an NA 944. Also, you need to use unleaded gas since leaded will destroy your catalytic converter.

 

Hello Porsche Doc,

I live in Istanbul, Turkey... Also, the original Driver's Manual that I have, states that I should use 98 octane. I guess... Because the manual is in German.

Any ideas?

So, in that case, should I use 98 octane unleaded? 100 would be better or worse?

Regards,

porsche_lover

 

I have an 85.5 manual. I mostly run 89 octane but on occasion run either 91/92 (depending on what I can get for premium). I see a slight miles/gallon increase but I do it mostly to clean the injectors. I try to stay away from 87 octane as I noticed a power loss when I have tried it in the past. If you use 89 or higher, you will be fine. If you see a light difference in price with premium, buy it. Please note that these observations are done on an almost stock car. Very slight performance increase with bigger exhaust and an K&N air filter. Also note this car has over 200k miles on it without being rebuilt (yet). The higher octane will give you performance boost but a huge hit in the wallet and is not required.

 

Gasoline in the US is rated differently than rest of the world, so you need to use what your manual states. You will see no difference in a non turbo car by running higher octane than what is recommended.

 

The usage and pricing of gasoline (or diesel), the results of factors such as oil prices, refining and distribution of gross costs, local demand, the strength of local currencies, local taxes and availability of local sources of gasoline (supply). Since fuels are traded worldwide the trade prices are samat.Kuluttajien the price paid is largely due to a national pricing policy.