[Oil Man]

As has been noted with a couple of excellent posts, a high volume station with modern pumps and equipment gives you the best odds that you'll fill up with fuel that has not been contaminated or broken down.

Top Tier is a set of quality standards that EVERY refiner in town meets at this point, that exceed EPA requirements for detergent additives in gasoline. In fact, at least in my part of the world, you would be hard pressed to find a gas station that does NOT sell Top Tier.

I'm a terminal operator for one of the larger refiners in the Western US, who own or distribute to the biggest brands in Southern California. And the amount of persistent old wives' tales and "wisdom" about the connection between brands, oil, gasoline and quality is staggering. People will snub one brand in favor of crossing the street and paying $.40/gallon more for gasoline that was delivered from the same tanker truck, or came from the same refinery.

When I was growing up, my own father refused to buy gas from the company I ended up going to work for, telling me that they made crappy gas from the lowest quality crude oil. I came to understand later that they really made great gasoline from crude oil from the Alaskan North Slope, which is to crude oil what filet mignon is to dinner. But because they were on every corner in L.A. and dimes cheaper per gallon that everyone else, it must be crap, right?

[Mark114]

I believe the injectors on a DI engine are more sensitive to fuel quality than port injectors. The detergents in the fuel keep the injectors clean too.

You can believe them or not but there have been a few threads and web articles that discuss the problem on DI engines where the fuel doesn't immediately vaporize and washes oil off the cylinder walls to form a mixture that is prone to detonation. The articles claim during testing they found that certain combinations of fuel and oil additives are more or less prone to this issue. The article didn't name brands or additives due to the proprietary information.

[oneredry]

I use shell personally. I used to work at a dealer way back when and when they started to put DI injection into cars a lot of the times, the injectors would go bad. (almost daily we would see this) we started to accumulate information from the customer, come to find out they were using speedway and BP gas. Just as a trial run, we asked the customers to try a top tier (speedway and BP are not) and never had a problem since. (yes we had to replace the injectors.) so I started to tell people to shop at a top tier such as shell. about a month later, I got a call from corporate speedway saying they could sue me for (I forgot the terminology) well since then, I did not mention anymore about going to shop elsewhere.

[JCunningham]

you have to pay to be on the top tier list.

[redcoats1976]

Originally Posted by 00 Trans Ram

Here's the thing with "gas". And, this information is from a Sunoco engineer that supplied gas to Indycar at the NOLA Motorsports race back in 15.

Almost all "gas" is the same. Think about it - how many companies in the world drill, refine, then distribute gasoline? A half-dozen or so. And the refining process is identical for all of them. Moreover, they often receive their crude from the same places. In other words, the gas you get from Shell and the gas you get from Exxon may have originated from the same well in the Gulf of Mexico.

What makes gas different are the additives that are put into it. The most important of those additives are things to keep valves clean and valve seals lubricated. But, as stated, those additives don't help direct-injected cars. So, for us, the only real differentiators are corrosion inhibitors, emulsifiers, and some other things. And, these things don't play a huge roll in the quality of the gas.

So, we should just buy gas from anywhere, right? Well, not so fast. If you could pump gas directly from the supply truck, then yes. But, you're pumping from a tank in the ground. That brings up 2 problems.

First, how good is that tank? Does it keep water out? Is it airtight (keeps volatiles from evaporating)? The newer a tank is, the better for both of these (and some other) variables.

Second, how long has the gas been sitting in that tank? The long gas sits, the more water van be absorbed (humidity, condensation, etc.). And, the more likely that the volatiles will evaporate.

So, what you want to look for is the gas station that A) has the newest tanks (usually, also the gas station that LOOKS the newest or was built most recently) and, B) has the highest volume (gas is replaced often).

For me, that means going to Sam's Club. They just replaced all of their tanks a few years ago. And, I talked with an attendant (just ask, they usually know) and he said that they get 2 tankers every 3 days (roughly 1 tanker every 1.5 days). This means they are going through gas FAST.

interesting...there is a brand new race track gas station 1/2 mile from my house.it has 20 pumps and theres always about 4 being used.does this mean i should pass up the 30 year old shell station on my street corner for race track?

[keon718nyc]

I been only using Shell 93' since i picked up the car and nothing else. So far so good. Here is a old thread i made back in 16' about what gas station do some use - http://www.camaro6.com/forums/showthread.php?t=464929

[DangerZL1]

Originally Posted by redcoats1976

interesting...there is a brand new race track gas station 1/2 mile from my house.it has 20 pumps and theres always about 4 being used.does this mean i should pass up the 30 year old shell station on my street corner for race track?

I'd ask the manager of the station if the in ground tanks have been replaced and how often they get filled. I'd think that a station that sells a lot of gas and has newer equipment would likely average a higher quality gas.

[misterjaayy]

Originally Posted by Whipple Charged

As one that pushes the limits on nearly every motor, I can tell you with 100% confidence those additives are very different. We only recommend true top tier gas which is Shell, Unocal, Chevron, Sunoco, Mobil and the big names. I can tell you, Costco gas will not react anything like any of the others listed. The difference in detonation is severe, Costco 91 vs Chevron 91, back to back was a difference of 4 degree's of spark, which resulted in 40+ RWHP. We've tested many others in real world and its very important when modified. If your stock, its not as critical.

This. I have seen other posts on here comparing performance with Chevron or Shell vs Costco or other discount gas stations and the difference in hp output is significant. Nothing but Chevron or Shell for me. Why try and save five or six bucks a fill up when you paid 40-65k on a performance car? Get the most out of the engine you paid big bucks for.

[Software Guy]

I use Sunoco because it's a new station and close to my house. My Firehawk can't stand Kwik Fill Gas. Other stations are hit and miss so I simply pay for what works in my car with no issues. The Camaro does not seem to care. 17 year old car vs 1 yea old.

[Need4Camaro]

Originally Posted by oneredry

I use shell personally. I used to work at a dealer way back when and when they started to put DI injection into cars a lot of the times, the injectors would go bad. (almost daily we would see this) we started to accumulate information from the customer, come to find out they were using speedway and BP gas. Just as a trial run, we asked the customers to try a top tier (speedway and BP are not) and never had a problem since. (yes we had to replace the injectors.) so I started to tell people to shop at a top tier such as shell. about a month later, I got a call from corporate speedway saying they could sue me for (I forgot the terminology) well since then, I did not mention anymore about going to shop elsewhere.

Are they f*cking serious?

[SSDanny]

Originally Posted by Whipple Charged

As one that pushes the limits on nearly every motor, I can tell you with 100% confidence those additives are very different. We only recommend true top tier gas which is Shell, Unocal, Chevron, Sunoco, Mobil and the big names. I can tell you, Costco gas will not react anything like any of the others listed. The difference in detonation is severe, Costco 91 vs Chevron 91, back to back was a difference of 4 degree's of spark, which resulted in 40+ RWHP. We've tested many others in real world and its very important when modified. If your stock, its not as critical.

Wait, Costco gas can cost you 40whp??

[Allez]

Costco is a Top Tier gas provider: http://www.toptiergas.com/licensedbrands/

[camaro5]

Currently, many gasoline retailers provide fuels with lower-quality additive packages that can build up deposits on fuel injectors and on intake valves

Others can build up deposits in combustion chambers and may lead to intake valve sticking.

These lower levels of additives can have negative impacts on engine performance and vehicle responsiveness.

http://www.toptiergas.com/why/

:

[motorhead]

Originally Posted by oneredry

I use shell personally. I used to work at a dealer way back when and when they started to put DI injection into cars a lot of the times, the injectors would go bad. (almost daily we would see this) we started to accumulate information from the customer, come to find out they were using speedway and BP gas. Just as a trial run, we asked the customers to try a top tier (speedway and BP are not) and never had a problem since. (yes we had to replace the injectors.) so I started to tell people to shop at a top tier such as shell. about a month later, I got a call from corporate speedway saying they could sue me for (I forgot the terminology) well since then, I did not mention anymore about going to shop elsewhere.

Sue you for what? I would have told them to "F" off. Manufacturers put it in their owner's manual and other publications. They are telling far more people to use Toptier than you telling your customers.