Hi all, I've gotten some good advice since joining the forum on some basic questions. Here is another one concerning gas. I recently bought a 1974 2.0 with 51000 original miles. The life long Porsche guy I bought it from said he burned only name brand high octane. I've gotten advice from another source that I know to be knowledgeable on 914's that said burn the cheapest gas I can find (it had something to do with the hardness of the valves?).

If the car is "used to" the high octane, will it react adversely to a change? What would I look (or listen) for if it does? Like so many things, I realize it is subject to opinion and I'm seeking more from anyone who cares to offer it. Thanks

Steve

Mine does not run as well with regular, but it will run.

I tried 87 and 89 when gas prices went over 3 bucks. one tank full of each and I was back to the 91. Car ran like crap straight from the pump.

I have a 75 2.7L Six cis and it always runs better on high octane, It still says on the car to runs 91 octane from the original '75 2.0L

I have a '74 2.0L motor has 160K miles. It just spent the last year of its life doing DEs Time Trials and AXs. About 8 track days and 10 AXs in all. For all of those events I burned nothing but 87 octane regular. Car ran perfectly with no pinging or knocking...Was driven to and from some of the events and on the street as well with no ill effects.
I will say that the motor is now apart to be rebuilt....no the motor did not blow or have any problems other than bad valve guides.

Once the motor is rebuilt I will try the regular again and see if it continues to work...
If your motor is tuned correctly I see no reason why it won't run on regular just fine.

my observartions....yours may differ.

God, I have to ditto that remark, and tell URY914 to do the same.

Yeah, I tried throttling down the octane for a tank or so, and even after compensating with a bit of timing adjustment, I thought I was going to need a magnet to catch the valves ready to fly out the tailpipe.

It just seems to "run" better with, at-a-minimum, 91 octane. At least through seat-of-the-pants.