ufager

I drive a 2011 W212 bluetec diesel, W210 inline 6 gas, BMW E60 v8, and last but not least an older Toyota 4 cyl standard pickup truck with about 260,000 miles on the odometer. I have owned all vehicles since they were new, and gotten to know them very well. During the last year I noticed problems with the pickup truck engine missing and running rough, especially driving up a hill or sometimes at freeway speeds on inclines. I did the usual to correct the problems, checked the ignition system, changed the spark plugs, etc. And I also adjusted the valves and added Techron gas treatment and used (Costco) premium gas to clean the fuel injection system, but to no avail.
Then it occured to me that the problem may not be with my pickup truck, but with the gasoline that I have been using. I have been using primarily Costco gas over the years for the pickup truck (regular and lately premium). So I recently got a full tank of Chevron premium and my pickup truck has been running perfect and just like new ever since! On my second tank of gas I am trying Mobile premium to see if that will also work.
I have never previously subscribed to the idea that the quality of gasoline can be all that different between discount gas and major brands. After this experience I am now changing my mind. I will use my old Toyota pickup to test the brand name gas before I use it in my other cars. And for the W212 bluetec, I am currently using Mobile diesel fuel.

kingofire

This site is your friend. www.toptiergas.com

K-A

Thanks for that info! I sometimes wonder if the "brand gasses" are just a gimmick, but looks like that's not the case.

Anyone know how Arco fares?

220S

I think Arco su*ks. It's cheap gas plus they're so cheap that they don't even allow you to use credit cards.

In SoCal I use Chevron almost exclusively. Plus I toss in some Techron once a month (even though Chevron has some Techron additive in it already.) I have used 100 octane 76 but it's getting harder to find. Plus I really didn't notice any performance gains (both in the AMG and my Porsche.)

hyperion667

(both in the AMG and my Porsche.) 220S


DAYUM!!

RNBRAD

And you shouldn't notice any difference other than maybe loss of performance. I build race engines as a hobby. You run a certain octane gas based on your compression and timing. You set your compression and timing based on the type of racing you do and what rpm you want most of the power. All cars are designed to use a certain octane gas for maximum efficiency and power. If you run a 100 octane gas, you gain nothing because your compression doesn't change to support the less combustable gas. If you don't have increased compression to support it, you actually lose power. It's doing nothing other than draining your wallet.

El Cid

Have used BP gas for ages and before that Amoco. No problems. Also add Techron about every 5,000 miles or so. Interestingly, MB dealer adds Techron as part of their regular servicing.
One problem with future gas is that the Agri-business and Ethonol industry have convinced government to "recommend" stations provide E15 (15% ethanol) fuels. First step before mandating it?
If stations have to dedicate pumps and tanks to E-15, they will abandon E-10 just as they abandoned pure gasoline. Seriously doubt the distributors will have separate trucks and drivers for E10, E15 and pure.
I have a 97 Mazda (Ford) pick-up and I add Sta-Bilt every time I get gas since I cannot find pure gasoline locally.

kingofire

I was reading the MSDS for Techron and it seems that they no longer use PEA. I have now migrated towards Shell Gumout Regane and Red Line SI-1. Have used it at every 5000 mile intervals. On my prior cars I have used BG 44K every 30,000 miles as well with great results.

Arrie

Very nice post! I'm so happy to see someone else thinks about this the way I do.

There are a lot of posts on other car forums where people claim that they get better gas mileage and more power with higher octane gas. This is true but what these folks don't understand is that the engines in the cars they drive are made for high octane fuel. Modern car engines are built to handle different octanes, i.e. our MBs will run with 87 octane fuel but not nearly as well as with 91 or 93 octane. Knock sensors in engines adjust timing and perhaps intake air flow etc. to keep premature ignition under control.

I have seen a lot of Japanese car brands that advertice 87 octane is fine to use but I'm pretty sure these engines are made to run with 91 - 95 or even higher octane. Engine like this for sure will perform better with higher octane fuel and folks first driving these cars with 87 octane are just amazed how much better high octane fuel is....!

And the comment running higher octane than what the engine needs is waste of money is dead on. More compression "tolerance" in the fuel than what is needed does not give any benefit for the engine performance.

Then one thing I want to mention here, perhaps unnecessarily, is that octane rating of the fuel does not change the energy content of the fuel. This is a very common misunderstanding amongst a lot of people as they think that better power and fuel mileage comes from bigger energy content of higer octane fuel. This is not the case.

RNBRAD

True, people misinterpret high octane as more energy. There is only 1 way to get more energy out of your gas with no motor changes, that is using oxygenated fuel, plain and simple. To put it simple, the higher the octane fuel the "lower" the flamability. This prevents preignition in motors with high compression. So when a person uses higher octane than is supported by the motors compression, they have a slower and later burn that affects their horsepower and MPG.

220S

When I have used it, I mixed 91 (the highest available in CA) with the 100. I never used it 100%. That would be senseless unless I had a 91/100 ECU flash or something. A blending chart gets the right ratio. (And the 76 100 octane is apparently only 96.)

With the crappy gas here in CA, I'm always concerned with using a fuel high enough in octane to satisfy the engine under all types of conditions. Using the 76 racing gas with the 91 gives me some peace of mind sometimes. At least I can get it to 93.

I personally don't think the AMG runs that great on 91. It seems happy in the 93-95 range. The Porsche seems to also. As I said in other my post it's not noticeable performance, but it just seems to run better

That said, it's harder to find these days anyway. Most of the time I use the straight 91 which is all we can get.

El Cid

However, isn't bottom line to use whatever the manufacturer recommends? Example, E350 requires 91 Octane. Ariound here, I can get 87, 89 or 93 octane, so I use the 93.
I think some Japanese cars recommend one level, but require a lower one. Whatever that means.

RNBRAD

Yea exactly! Your car only benefits from ahigher octane to a certain point and that point is usually the recommended octane rating. You can run 93 to 105 but won't do anything but lighten your wallet. You can run 86 in these cars as well without a problem, though your efficiency may suffer a tad, because your car will retard it's timing for the lower octane gas. Won't harm your motor a bit.

ufager

After having tested major gas brands in my old Toyota pickup, I have found that it will run best, and just like new, on Chevron regular gas. This has taught me a lesson about using cheaper "discount gas" brands in any of my cars. (see below for my previous posting on the subject & background)

"I drive a 2011 W212 bluetec diesel, W210 inline 6 gas, BMW E60 v8, and last but not least an older Toyota 4 cyl standard pickup truck with about 260,000 miles on the odometer. I have owned all vehicles since they were new, and gotten to know them very well. During the last year I noticed problems with the pickup truck engine missing and running rough, especially driving up a hill or sometimes at freeway speeds on inclines. I did the usual to correct the problems, checked the ignition system, changed the spark plugs, etc. And I also adjusted the valves and added Techron gas treatment and used (Costco) premium gas to clean the fuel injection system, but to no avail.
Then it occured to me that the problem may not be with my pickup truck, but with the gasoline that I have been using. I have been using primarily Costco gas over the years for the pickup truck (regular and lately premium). So I recently got a full tank of Chevron premium and my pickup truck has been running perfect and just like new ever since! On my second tank of gas I am trying Mobile premium to see if that will also work.
I have never previously subscribed to the idea that the quality of gasoline can be all that different between discount gas and major brands. After this experience I am now changing my mind. I will use my old Toyota pickup to test the brand name gas before I use it in my other cars. And for the W212 bluetec, I am currently using Mobile diesel fuel. "

Racing Dad

i've noticed the same thing. With my old BMW 550i, it was a huge difference in gas mileage. i onnly did it trwice because i had no choice, once was a no name brand gas station out in the middle of no where. And another one was at ARCO.

it was a noticeable difference. Gas mileage was poor, performance decreased, felt more sluggish, didn't know what it was, but after it went away, i realized it was probably the gas.

DNAPoPo

Whoah, so it might be the costco gas giving you the problems? I've been using costco gas for several years now with no problems... please keep us posted