[BentZero]

I just noticed that my gas station has an ethanol free option. i think this used to be a recommendation for the N55. Is that still the case or should I continue to use the higher grade octane?

[Mywifes335]

Higher octane for sure.

[bimmerfile]

Originally Posted by BentZero

I just noticed that my gas station has an ethanol free option. i think this used to be a recommendation for the N55. Is that still the case or should I continue to use the higher grade octane?

Only use a Top Tier (aka Tier 1) gasoline, at least 91 octane (ethanol free preferred).

[BentZero]

Originally Posted by bimmerfile

Use a Top Tier (aka Tier 1) gasoline, at least 91 octane (ethanol free preferred).

Definitely referenced the list to make sure that they're a tier 1 station. I also don't get gas if I see the fuel truck there. Refilling those tanks stirs up sediment.

[orangeglim]

Where does one find out if a station is a top tier station?

[BentZero]

Originally Posted by orangeglim

Where does one find out if a station is a top tier station?

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

[orangeglim]

So its as simple as the brand name on the station then?

[cmiller219]

We only have 92 with 10% octane here on the island so that's what I have to use

[RoundelM3]

Never, ever use 87 octane fuel in your BMW - the effective compression ratio in these forced-induction engines requires 91 octane at a minimum. Use of 87 octane will reduce power and cause detonation that the ECU can't compensate for by backing off the timing. There's nothing wrong with 10% ethanol at 91 or 93 octane levels, although ethanol-free would be ideal.

[BentZero]

Originally Posted by roundel335

Never, ever use 87 octane fuel in your BMW - the effective compression ratio in these forced-induction engines requires 91 octane at a minimum. Use of 87 octane will reduce power and cause detonation that the ECU can't compensate for by backing off the timing. There's nothing wrong with 10% ethanol at 91 or 93 octane levels, although ethanol-free would be ideal.

Thanks for the info. sadly I've yet to find 90+ ethanol free.

[Sportstick]

Originally Posted by orangeglim

So its as simple as the brand name on the station then?

Essentially, yes. Base gasoline is fairly generic and you will see a variety of refinery named-trucks delivering the product. The brand name which makes Shell, Shell, BP, BP, etc. is the package of proprietary additives which the station adds to their underground tanks. So, follow the top tier brand name for the best detergent packages. BTW, Costco premium has a particularly strong package, possibly only second to the additional new lubricant in Shell Nitro (although Nitro isn't available everywhere...we see it advertised but I can't find it.)

[Beartato]

As someone who just puts in the local Kroger chain (Smiths) gasoline, I might have to look into this Top Tier gasoline thing.

[matthibodeau]

91 octane 0% ethanol (Shell V-Power Nitro) or 93 octane 10% ethanol (Petro-Canada)
Which would you say is better guys?

Note: I personally always use Shell V-Power Nitro

[Sportstick]

Originally Posted by matthibodeau

91 octane 0% ethanol (Shell V-Power Nitro) or 93 octane 10% ethanol (Petro-Canada)
Which would you say is better guys?

Note: I personally always use Shell V-Power Nitro

Once you meet the octane requirements of an engine, additional octane is waste.

[BentZero]

Originally Posted by Sportstick

Once you meet the octane requirements of an engine, additional octane is waste.

This is true. I'd go ethanol free if given the choice.

[dalrx]

I got an ecu tune and use PetroCanada 94 ...tried lower grade shell nitro not as responsive.

[BeeDrill]

Originally Posted by dalrx

I got an ecu tune and use PetroCanada 94 ...tried lower grade shell nitro not as responsive.

I always wondered which was better because I've heard for years that all Canadian gas is pretty shitty and doesn't really live up to the octane ratings, but didn't know how true it really was. Glad to hear the 94 is actually a higher effective octane.

[bimmerfile]

Originally Posted by BeeDrill

I always wondered which was better because I've heard for years that all Canadian gas is pretty shitty and doesn't really live up to the octane ratings, but didn't know how true it really was. Glad to hear the 94 is actually a higher effective octane.

Where have you been hearing or reading THAT?

[BentZero]

Originally Posted by dalrx

I got an ecu tune and use PetroCanada 94 ...tried lower grade shell nitro not as responsive.

Thus raising the required octane rating for your car. How do you like the tune?

[BeeDrill]

Originally Posted by bimmerfile

Where have you been hearing or reading THAT?

Subaru forums. I'm coming from driving WRX's.

[ocN55]

Originally Posted by BeeDrill

Subaru forums. I'm coming from driving WRX's.

A car that is very octane sensitive

[BeeDrill]

Originally Posted by ocN55

A car that is very octane sensitive

Yeah, even more so with the 2015 using the 2.0 FA20DIT. I'd felt it pull timing on me on more than one occasion and it was stock. Seemed like it liked Petro-Can 94 better than Shell 91, but I was never really sure.