MiataR

As a legacy from when I had a turbo car that required higher than 91 octane, I've generally put Sunoco gas in all my cars. Last weekend, I decided to put Shell 91 in the Porsche (no Sunoco within convenient driving range).

Since then, I've noticed that the engine has to turn a few times before it fires up on start up, and the idle is a bit rough for about 10 sec. Didn't link it to the gas until last night when I filled up with Sunoco 94. I haven't had a bad start since. Is it all in my head?

I've generally stayed away from Esso (high sulfer content?), but haven't heard a bad thing about Shell before. Any one have a simillar experience with Shell gas? What do you guys usually run?

b5audia4

Were you turning into the Sunoco by Winston Churchill/403? Saw a nice looking 3.2 Carrera with those black RUF rims. Nice car!

Jaak Lepson

You must of had bad gas from that station. Sunoco 94 has 10% ethenol mixed in with the gas. Shell 91 is 100% gasoline. Do a search on Ethanol and it's combustable properties vs gasoline and you will be amazed at the difference.

I use nothing but Shell 91 in my 951. The car runs better with less lag and a bit more umph when the turbo kicks in (still in storage ). Friends who I have talked to have switched to Shell 91 and have noticed the difference; better milage, better performance etc. Vehicles need a bit of time and a few tanks to get used to a new blend of gas.

Dale Gribble

i switched down to sunoco 91 just because my car is n/a and doesn't really benifit from the additional octane.

i didn't know that shell didn't have ethanol. i thought all pump gas had to have 10% of it by law.

does shell have a points program?

btw, there was an excellent chart of the different ethanol mix gases and the power gain/loss, fuel economy change and other scientific stuff in one of the Panorama's..i'll see if i can scan it and upload it.

pongobaz

Funny, I used to use Sunoco but switched to Shell because Sunoco 94 uses up to 10% ethanol. Tailpipes used to have black sooty deposit with Sunoco but not with Shell. Could be the gas station itself that's the problem (dirty tanks?).

Dale Gribble

could be,

but doubtfull. anything the tank doesn't filter out itself will be picked up by your own fuel filter.

Jaak Lepson

Airmiles ... maybe we can get you overseas and get you a mail order bride .... will take the pressure off zookie ....

Jaak Lepson

Could be water due to the spring runoff. Also ... if the stations tank was low it could be mixed with the sludge on the bottom.

BTW ... there is a Petro-Canada station at Vic Park & Ellesmere that seems to pump nothing but premium gas ... including 87 pumps. A friend put me onto this ... just down the street from home. The Edge seems to run better on their gas.

Dale Gribble

^ define pumps only premium?
their tanks are screwed up so the 87 button gives me 91?

PPo

I have always run the Shell 91 octane on my modified 951. It always ran better on it at the track and on the street compared to Sunoco 94. However, I have a custom engine management system so that may be a factor...

Hope this helps...

-Patrick

MiataR

Yup, that was me. You must have not been driving a p-car, else I would have waved.

Jaak Lepson

They only fill with 91 .... sometimes a Co will fill only with one type to grab market share in an area. Seems this one always seems to have more customers than others. Don't know if it is 91 ... but the old LR and the Edge behave as if it was ...

MiataR

Then I'm at a loss to explain my issue. I'll have to try another tank at a different station. Will report back on my results.

Omar, I would be interested in that chart... though something Canadian/Ontario specific would be better. I'll need to dig up a website that lists the chemical breakdown for each station type.

Thanks guys.

Zookie

i have been using Sunoco 94 since i got my car, no issues... the Dealer suggested 94 over 91... Handbook say 93...

MiataR

That seems to be the trade off... 94 + 10% ethanol or 91 w/o ethanol.