I've never had any problems with any brand I've used so far. Shell, BP, Mobil, and I think I've used Marathon once or twice. I pound the motor regularly. 17 vac. (~14k on the motor...) and no idle problems. It's all 93 over here. We used to have Sunocos a long time ago. There used to be one next to my old house, but they've since packed up and headed out. I guess in most cases you're not going to know if you put crap gas in until it's too late anyway. Oh well...

 

Correction - 93 octane gas was put in. I don't think we have 94 octane gas here.

 

I had a Porsche 928 GTS a while back. The car ran perfect until I went to a Texaco and filled up. I got about a mile down the road and the car ran like crap. After the dealer and every other **** couldn't figure it out I did. I dropped the tank, drained the nasty *** gas out, replaced the fuel filter, injector head and all the injectors etc. 4500 dollars later the car was fixed. (bad gas).

My suggestions are:
1) Avoid Texaco and Shell as well as no name gas stations.
2) Never pump gas if there is a semi who either is getting ready to fill up the tanks or has just finished. If they are low you suck up the crap on the bottom and if he just filled the tanks the crap was just disturbed and is now floating in all the new gas.

Always use high test and wait to see how the car runs after a new load of fuel, I suggest not boosting hard for a couple miles.

Just my 02...

 

This is an interesting theory but I have a couple of questions.

1) Are you saying that the "crap" is at the bottom? Or at the top? In either case, how do you that the "crap" is denser/less dense than good gas?

2) How do you know that when you pump gas, you are pumping the gas from the top? Intuitively, the opposite must be true only because it is easier to have the pipe for the pump at the bottom.

I say your theory doesn't fly.

 

is chevron safe??

 

Lets use basic common sense. If the truck pumps the gas it stirs the whole pot, that means the junk is in ALL the gas, whether from the bottom (sediment and water) or the lighter stuff on the top.
For you, pump away.

 

Did you know a person can not swim in gasoline because you can not displace enough weight per volume .Gasoline is lighter than water, we can swim in water .

 

At all the Sunocos I've been to (admittedly not very many) they have the 94 at a separate island and the tank is located away from the 87, 89, 93 ones. I think it minimizes the risk of a mix up due to human error.

 

Is the car still doing this? Are you seeing the telltale signs of a blown motor---shaking UIM, fluctuating vacuum (with a constant idle), chugging sound at idle? Hopefully it's ok. It you're idling at 500 rpms, your vacuum will be low as well.

As far as MMO goes, not sure if I'd put that in the tank. Check out the contents of the stuff--it's more of a cleaner than a lubricant IIRC.

Rich

 

Say it ain't so. And I thought that pool outside was just fer da fishes

 

Sure. Hehe. I've used it before with no ill effects. I think Mr rx7 tt gave a good piece of advice: don't boost the car for a bit after filling up to get a feel for how she's running. Of course, I really enjoy tearing *** out of the gas station, so I prolly won't practice what I preach .

Kinda sucks that we have to worry about this kinda stuff, but I suppose it comes with the territory.

Rich

 

Personal Experience?

I have Sunoco in FL, but the bastards don't carry 94. I had been using it for a while when I lived in NJ. I called them up and asked why, and their response was "There wasn't enough demand for it". Damn stupid Floridians can't vote now they don't know how to pick fuel

As far as fuel is concerned, I trust Mobil (and the Sunoco 94). I've never had a problem with Mobil, and their oils are just as good as their fuel. I read this article on them a while back. This is why I use their premix. Their oil's leave the least amount of carbon deposits (and other ****) as opposed to other oils. I had a chart on this, but I lost it when my harddrive crashed.

 

Rich, UIM is not shaking, slight surging sound at idle, and unstable idle. I used mmo in my 2 first gens for years. I'm not sure of whats in it. Anyway, I'm paying Steve a visit today to have him look at it.
Paul

 

Ok, sounds like your apex seals are most likely undamaged. I'm sure Steve will clear the problem up.

later man--
Rich

 

Can somebody please TECHNICALLY explain why 87 would cause my engine to blow up.

I can understand using low quality fuel for extended period of time can have a negative effect on the engine life, but one tank??? The FD can't be that fragile can it?

If this is the case, **** it man I'm going the V8 route... I can deal with the boost/creep/heat/syncro problems, and 100k engine life, along with the cost of maintaining it running. But not the issue of one bad tank of gas. I love my FD but I love it more when it's running.

 

Its a nasty thing called "detonation", we've all heard engine knock. Well detonation is a severe knock. In a piston engine knock is sound pistons make rattling in the block. I'm not a big rotor expert, but I don't believe the rotors upon detonation have anywhere to move. Therefore the apex seals break. HELP!! needed on this.

 

Nope. It really depends on where the "crap" is, where the pipe is that leads to the nozzle and where the pipe is that pumps in the new gas into the tank.

Let's assume that you are only concerned about water and sediment which would be at the bottom of the tank. Let's also assume that the pipe that leads to the nozzle is at the bottom of the tank. When is the best time to pump gas into your car? It's proabably not a bad idea to pump during or right after the tank has been filled since it will "dilute" the crap. Whereas, if all the layers are separated and you pump and get the gas and the "crap" from the bottom, you are much worse off.

My point is unless you know the specifics of the design of the tank, and what "crap" there is in the tank(its density relative to gas), you can not make an INTELLIGENT decision.

Never assume.

 

i used to work at a sunoco station. the one i worked at got regular 87 and 94 octane. to get the different gas it just blends it. when you get ultra 94. you are getting it straight from the one tank

 

I don't know if you were replying to my post but I'll ask anyway.

How would a lower octane fuel cause detonation. I am looking for a technical answer here with an explanation of why would 87 cause it to blow up and not 91. It just dosen't seem plausable to me unless it actually was bad gas. Not just a mix up between 87 and 91 (or 93 for other states)

 

But that's exactly what octane rating is; a rating based on a fuel's ability to resist combustion from high pressures alone as opposed to from an actual spark. Something along those lines anyway.

 

someone tell me more about race gas or 110 octane...is this safe to run in a stock engine...what should i avoid? I know nothing about this stuff. thanks

 

Montego,
This link will explain it to you simply.

http://auto.howstuffworks.com/question90.htm/printable

 

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. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight -- that is what makes the engine "high performance." The disadvantage is that the gasoline for your engine costs more.

There ya go montego.

 

110 Octane is leaded. You can't run leaded gas with a catalytic converter. It will also foul up your 02 sensor faster. It is safe to run with a stock engine though techincally, but a midpipe would be advisable.

 

thanks shinoby and crazysuprakid