[jskrilla]

How many of you put the following in your vehicle? Also state the car that you drive, whether it's an 228i or an m235! Do you think it honestly makes a difference?

Regular

Plus

Premium

[nike001]

Sunoco 91 Premium all the time - it's right across from my work so it's super convienent as well.

It does make a difference.

[Iceman51sn]

M235i with 91. I'd use 93 if we had it out here and yes makes a difference.

[SmoWilly]

91 Octane as that is all that is available in the rocky Mountain areas. For the extra dime a gallon (or $1.40 more a fill up), I don't give it a second thought in a $50k vehicle.

M235i Convertible.

[nachob]

Premium! the car was designed for premium and actually what we get here is already lower quality than the European stuff. The thing you have to remember is that if you put lower octane fuel in a high compression motor, it will retard the timing and richen the mixture to prevent detonation. This means less power and more consumption both from the richer mixture and pressing the gas more to make up for the power loss. You end up almost not saving any money on the cheaper gas. It's been a long time but I actually worked in the test department for an IMSA GTP team testing and flowing injectors. We found that Techron really did keep injectors cleaner and used it to flow test/clean injectors after every race. I still use Techron and Chevron fuel for this reason.

With our direct injection motors you no longer get the benefit of detergents cleaning the intake valves but keeping injector spray patterns consistent is still a great benefit. Many swear by Shell fuel and it's probably good, but I have not had first hand testing like I had with Techron so for now I take it with a grain of salt.

[Sportstick]

Costco premium. Not only a top tier fuel, but in excess of requirements. Octane rating has been discussed, but they have come up with a great detergent package.

http://www.toptiergas.com/retailers.html

http://www.costco.com/kirkland-signature-gasoline.html

[DanG]

ARCO top tier premium for my M235i.

[Goettler_Boost]

Originally Posted by Sportstick

Costco premium. Not only a top tier fuel, but in excess of requirements. Octane rating has been discussed, but they have come up with a great detergent package.

http://www.toptiergas.com/retailers.html

http://www.costco.com/kirkland-signature-gasoline.html

Interesting! I'm going to start using that gas now.

[CameronCrazy]

Shell VPower 93 Octane

M235i.

[overcoil]

Premium from stations that have new in ground tanks - and are constantly busy.
Exxon, Shell, BP

A tanker driver told me the gas pumps (or tanks) do have their own filter systems.
As eluded to above higher-octane fuel doesn't detonate as easily as a lesser octane.

M235

[pikcachu]

Originally Posted by Sportstick

Costco premium. Not only a top tier fuel, but in excess of requirements. Octane rating has been discussed, but they have come up with a great detergent package.

http://www.toptiergas.com/retailers.html

http://www.costco.com/kirkland-signature-gasoline.html

+1 and 0.30 cheaper than most places

[Liquidpaper]

Whether you're in the 228 or 235, you need to run at least 89, and preferably 91 (or higher). The compression ratio (without boost) is already about 10.5:1, and with boost, its closer to 15:1. The lower octane fuel will pre-detonate, causing knock, and the engine to retard its timing/lose power.

Personally, I use 91 all the time (its be best we can get in CA), and never from ARCO, but anywhere else is usually fine.

[rar2ooo]

i'm in shock to see that the usa has lower octane fuels almost everywhere u go..
i live in belgium and all we can get is 95 and 98..
why is that?

[BD_F22]

Originally Posted by CameronCrazy

Shell VPower 93 Octane

M235i.

+1 usually only use Shell 93 V-Power on my m235i

[Liquidpaper]

Originally Posted by rar2ooo

i'm in shock to see that the usa has lower octane fuels almost everywhere u go..
i live in belgium and all we can get is 95 and 98..
why is that?

Different rating system. 91=95, 93=98. Its the AKI v. RON standard for calculating octane rating. The fuel is the same though.

[pikcachu]

Originally Posted by rar2ooo

i'm in shock to see that the usa has lower octane fuels almost everywhere u go..
i live in belgium and all we can get is 95 and 98..
why is that?

cause US use AKI and europe user RON

http://en.wikipedia.org/wiki/Octane_rating

98 RON = 93 AKI
95 RON = 91 AKI

[3.0L]

Premium 91 only in my car.

As to the 95 or 98 ratings in Europe and elsewhere, I believe their rating system is a little different than here in the USA. There's RON, MON, AKI. I think Europe uses RON, while the US uses an average of two or three methods.

[StephanieDiane]

93. I consider the cost difference negligible from 91. Few bucks a week? If the evidence for benefit were even just circumstantial, I'd still do it for the cost of a sandwich.

[2msport]

Costco as well. 91

[g18galvin]

On the gas cap door it says minimum ron91 so basically that's 87 octane gas here in north America?

[Killramos]

Shell V-Power 91 exclusively ( the only place in town that will guarantee me no ethanol )

91 is basically as high as we go here ( some stations offer a 94 octane high ethanol blend) Chevron in BC offers a 94 octane 0 ethanol but none of that here.

[Killramos]

Originally Posted by g18galvin

On the gas cap door it says minimum ron91 so basically that's 87 octane gas here in north America?

Do not fill your BMW with 87 in Canada...

right from the owners manual:

Gasoline quality
BMW recommends AKI 91.

Minimum fuel grade
BMW recommends AKI 89.

Do not use any gasoline below the minimum fuel grade as this may impair engine performance.

I think you read your door wrong.

Difference between RON, MON, and AKI
Because of the 8 to 12 octane number difference between RON and MON noted above, the AKI shown in Canada and the United States is 4 to 6 octane numbers lower than elsewhere in the world for the same fuel. This difference between RON and MON is known as the fuel's Sensitivity,[4] and is not typically published for those countries that use the Anti-Knock Index labeling system.

http://www.2addicts.com/forums/showthread.php?t=963815