Dave.. on most customer cars.. do you setup the AEM so it retards timing if knock is encountered?

 

What about Exxon and Hess....all the other stations around here are junk(Sheetz/,Rutters)??

 

All states test gasoline for contaminants and to verify you are getting 1 gallon if you are being charged for 1 gallon.

As for OCTANE TESTING it is not regulated anywhere that I have been able to find. Ohio and Michigan for sure 100% do NOT check octane, only Weights and Measures and purity from water and other contaminants.

Car and Driver magazine did a big report on this over a year ago and found out the same things I am relaying now.

Yes, I set up the AEM to ALWAYS retard timing if it hears knock.

 

Ohio is one of only four states that does not have a statewide gas-quality testing program. The others are Alaska, Nebraska and Pennsylvania.

 

ive been all over the country and never have heard of valero but ive heard or used all brands said so far.

 

Well, I just got back from Dynocomp, which is the only shop I let work on my car. As I mentioned earlier, I filled up on Valero 100 octane gas on Thursday and got my car tuned today.

Before the tuning, my car was making 290 HP on 91 octane at about 20lbs of boost. I'm running the Greddy T67 and cams, which are the only major engine mods I have on the car.

After the tune my car is making 360 HP at 25lbs of boost. The tuner stated that one aspect David is right; when he attempted to add more boost, the car started knocking and he left the tune @ 25lbs. I don't know at what point David had started running into knock issues with the 93 octane, but the car was on the dyno for about an hour and a half. I'll test other 100 octane fuels throughout the city to see if it is indeed the Valero gas that is cause of the knocking. I'm not a gas expert, but I don't see how gas that generally comes from the same refineries is causing problems of this sort, so stay tuned.

As for dyno sheets I will post them later.

 

The idea that there is "off brand" gasoline is a myth. All the gasoline you buy comes from a distribution point near you. These points are connected to common distribution pipelines.

Certain brands do add detergents but all in all the gasoline under the ground is going to be the same.

The ONLY difference you may see is the pumps are not set correctly to blend the proper octane from the tanks under the ground. This is the only place cheating can take place. The likely profit really would be minimal and not worth the risk but a I can see how it might happen. Independent station owners are the ones most likely to do this.

Does anyone really think Costco/Sunoco/BP want to get sued because the gasoline tested in someones tank after a car broke down was 91.5 octane? Not to mention the bad press.

Most likely what you guys are seeing is evidence of sediment from old tanks or old gas from rural stations that don't "tank up" much.

 

This is incorrect. There are various qualities of gas based on the additives added. Some of these improve combustion and reduce knock. Research Top Tier gas for the best gas available. It is a standard set by auto manufacturers for the minimum quality gas acceptable.

I saw 20 whp difference switching from Diamond Shamrock n/k/a Valero to Chevron, same tune, same dyno, same day, just 15 minutes apart. Both stations are on one of the busiest corners in town, so it's not old gas. The dyno owner was the one who told me that my problem was my gas. He said he sees it all the time with Valero gas.

 

Ask anyone that owns a dyno and they'll verify that gas quality varies and definitely effects power.

 

If one company, Valero is systematically misrepresenting the Octane they are blending does not mean that the gasoline they receive from distribution points is not the same as anyone else's.

Detergents, no matter the concentration aren't improving your Octane rating.

 

evol.ved, hang it up. There is an absolute, definite problem with Valero gasoline. I may just convince myself to get some and have it tested and then try to expose it on the local news. I am telling you, it's absolutely **** water. These same gas stations were Sunoco's a little over a year ago, I NEVER had anyone come to your shop from the Ohio Turnpike who had knocking issues, now that Valero has taken over what once were Sunoco's there is a definite problem with the fuel.

 

You need to reread my post. Some additives improve combustion efficiency and knock resistance and this will increase the power you make. If you're really interested, there's plenty of research from auto manufacturers on this subject. You can also ask anyone that owns a dyno and they'll tell you the same thing that David is saying, certain brands of gas always make more power than others.

 

This would be the only way that I would be really convinced that one type of gas is better than another. That way it is scientifically PROVEN that some gas is worse than others for performance. Also, I don't think Valero is doing this because the company is out to take people for their money; it could be very well that Valero is only putting out gas that has to meet the minimum state and federal requirements in order for it to be sold. Some companies will decide to go further than the minimum, but that's why you pay a premium for it.

As I offered in my previous post, I will be willing to put my car up for some gas testing. Of course, I'll have to talk to Dynocomp to see if they would be willing to donate time to help with the testing.

 

This has been researched before. Google "Top Tier" and you'll get all the research you want from the Petro Engineer Phds that work for the auto manufacturers.

 

You can buy a simple to use unit to test octane concentration for about 2k. Might be a handy item for you to have around.