jg4454

I started this thread to talk about gas. I have a 931, and I am happy that i only have to use regular gas. I'll start off by telling what I know about gasoline, from many years of expereince in the petroleum business. (Not gasoline, though.)

You only need the octane your engine needs. More octane does not equal higher performance. Octane is one of several chemicals added to gasoline, to reduce ping on high-compression engines. Go by the manufacturere's recommendation.

All carburator and feul-injector cleaners contain a lot of kerosene. Kerosene blends and burns well with gasoline and diesel fuel. It does clean out carbon deposits.

But I think Chevron with Techron is the best gas out there. Techron has something extra in it. My car really does run better on it. No relation to Chevron, here.

But, is the new Shell V-Power worth it? I would rather ask here than waste money on premium if 87 Chevron is all I need. Hope to hear from everybody. This forum has saved me money and kept me in a car I love.

No longer to be a 937, I'll settle for a 931
A rolling restoration, coming soon to the internet near you.
Running strong, mechanically perfect after $2500+-, and solid investments by the PO at more than $6000. A nice bonus on this deal.
Cosmetic I think about $3000-5000 for perfection.
I paid $3050 to win it on ebay, and it cost $750 to ship it here.
Yes, they can be expensive for a 155hp car.
But I love every second of driving this car.
Nobody else has one. Retro. Fast. Rare. Cool. Good mpg for a dream car. Nice.

Dennis Wilson

JG,

Agreed that for normal driving the lower octane is OK. Since I am running 1 bar boost with no intercooler, the extra $.08 for 93 octane is cheap insurance against blowing a head gasket due to preignition.

Techron is a good cleaner. Since we don't have Chevron stations here, I have used the additive type. I have noticed that Phillips has began selling fuel with a cleaning additive. I'm currently running it in my 931 and 928's. Time will tell if it is as good as techron.

'88-924S

Since my Bimmer days I've always run with Chevron. I always put 93 in mine out of habit and it's not THAT much more $$ these days. I can feel the difference between Chevron and others. Shell just had the high sulphur incident around here, the gas had too much sulphur which ruined the gas guages! The last thing I want is someone messing up my car and then having to send it to the dealer to be fixed(I'm assuming that'd be what I'd have to do for them to pay for it!)then I'd have to go back and fix what the dealer messed up!!

jg4454

If you buy Shell 89, it is blended at the pump to make it a mix of 87 and 93. The blend is 33% 93 and 66% 87. Since the new Shell V-Power claims to have 5 times the amount of cleaner as 87, I think 89 is a good buy.

JMTCW and YMMV.

Charlie944

I was curious as well with the new V-power. I always ran Amoco (BP) Ultimate clear 93oct with the occasional Redline SL-1 FI cleaner. But I have recently been putting the Shell V-power in to check it out...so far so good. Any reccomendations for getting a fuel sender unstuck without taking it out? On the 83' 944T with it sitting so long over its life the gas gauge does not go to the full mark. I dumped 1gal Toluene in the gas that had been sitting in the tank to raise the octane level, and was hoping it would help the sender.

Charlie944

Nice to see another 931 around too! My best friend has a 81' 931 that we are doing a full rebuild on currently, awesome cars! He had a chance to buy a Carrera GTS intercooler off of ebay for $900, but he thought it would go higher and ended up buying a set of BBS 16x8 and 10's 3-piece wheels instead, but he kicks him self now for not landing the intercooler. He is also interested in going with SCCA Class-D prod front end kit, and the Carrera GT rear fenders.
Happy Motoring!

Operator

I wanted to start a thread about V-Power but never got around to it. I just started using it 2 tanks ago, before I would usually get one of the top 2 octanes at Sunoco (they have 4 so both of the top 2 are pretty good). Honestly, it might be a placebo effect, but after I started using the V-Power I really felt like the engine ran smoother, revved easier, and the car was faster! I might be insane but I'm going to continue using it.. even though its probably the most expensive gas you can buy, especially around where I live. Yikes.

JBH

Just a few comments related to this discussion

Octane is a measure of the gasoline resistance to precombustion - it is not an additive. There is a pure compound, octane, that was probably the reference used to define the scale. Aromatics (like benzene, tolulene, etc.) and branched hydrocarbons (like iso-pentance, iso-octane, etc.) raise octane ratings. Straight chain hydrocarbons (all carbons linked linearly head to tail) reduce octane ratings.

Aromatic hydrocarbons are responsible for the buildup of carbon in your engine, valves, and fuel injectors. Most major brand gasoline use additives to prevent this. Techron is very good and it is used in all grades of Chevron gas. Octane levels are established at the refinery and the gas then moves through pipelines to distribution centers where the additives are introduced. All gasoline of a certain octane is the same (with one exception) as many companies use the same pipelines to move their gasoline - the additives are what differentiate one brand from another.

In some areas Amoco offers Ultimate Clear. This is, in my opinion, the best gasoline available as the company has added an extra processing step to remove the heavy aromatics that cause carbon build up. If you saw what is removed to make it clear, you would instantly recognize the benefits. This gasoline has to be especially transported to maintain its purity, so it does not go into the pipeline system used by other companies. I am certain this limits its distribution to areas that are close to the Amoco refineries that produce it.

If V-Power works for you, that great. Keep using it. I wish I could get higher octane gas here in WA. Be thankful for Sunoco and Amoco Ultimate.