High octane with +- 10% ethanol or no ethanol gas?

[FrankL]

So what gas and octane do you put in your BMW? I have a Marathon station close by and they sell a 90 octane no ethanol gas. I have been using 89 or 91 octane from usually Shell station.

[JeffinOregon]

Both ethanol and octane boosters help your engine run cooler. Particularly as you’re in Florida, either of those would be preferable to a lower octane without ethanol.

[RockCrusher]

Originally Posted by FrankL

So what gas and octane do you put in your BMW? I have a Marathon station close by and they sell a 90 octane no ethanol gas. I have been using 89 or 91 octane from usually Shell station.

You should use the octane called for in the owners manual. Usually it is 91.

After moving from CA to AR in August 2020 I had a chance to fuel my various cars with 91 E10 or 91 ethanol free. I could not tell the difference other than 91 ethanol free was more expensive by about $0.30/gallon or thereabouts than 91 E10.

As for using an octane higher than 91, more recently Maverik stations in my area offer 93 (E10) at the same price as 91 (ethanol free). I filled the M8 tank with some 93 and the M8 engine *loved* 93.

I'd run 93 all the time but it is not a top tier fuel. And yes there is a difference.

A few months ago curious I fueled the M8 with a top tier fuel: Phillips 66 91; and the engine ran better after burning through about 1/2 tank of 91 top tier fuel.

My 2nd vehicle, a Honda Ridgeline, got Phillips 66 87 top tier fuel and the engine ran better, too.

So for the last few months both the M8 and my Ridgeline get fueled with Phillips 66. The M8 with 91 the Ridgeline with 87 which what the manual calls for under normal usage.

Oh, yeah I pay more for the top tier fuel -- but not enough I even bother to recall what it is -- but the difference in how both engines run with top tier fuel made a believer out of me.

[TimmyTurbos]

Top tier ONLY. Spend a few cents extra today and save a few hundred tomorrow. I personally only run Shell V Nitro 93

[dosmildos]

Maybe it’s self persuasion but I have a similar perception. The engines in our cars (N63TU & B48) seem to run better with Top Tier fuel. Hype? Just my impression.

[TimmyTurbos]

Originally Posted by RockCrusher

You should use the octane called for in the owners manual. Usually it is 91.

After moving from CA to AR in August 2020 I had a chance to fuel my various cars with 91 E10 or 91 ethanol free. I could not tell the difference other than 91 ethanol free was more expensive by about $0.30/gallon or thereabouts than 91 E10.

As for using an octane higher than 91, more recently Maverik stations in my area offer 93 (E10) at the same price as 91 (ethanol free). I filled the M8 tank with some 93 and the M8 engine *loved* 93.

I'd run 93 all the time but it is not a top tier fuel. And yes there is a difference.

A few months ago curious I fueled the M8 with a top tier fuel: Phillips 66 91; and the engine ran better after burning through about 1/2 tank of 91 top tier fuel.

My 2nd vehicle, a Honda Ridgeline, got Phillips 66 87 top tier fuel and the engine ran better, too.

So for the last few months both the M8 and my Ridgeline get fueled with Phillips 66. The M8 with 91 the Ridgeline with 87 which what the manual calls for under normal usage.

Oh, yeah I pay more for the top tier fuel -- but not enough I even bother to recall what it is -- but the difference in how both engines run with top tier fuel made a believer out of me.

It kills me every time I see someone with a nice ride filling up at WaWa or somewhere. Most people don't even know about top tier. Good on you, sir! Your cars are happy! Haha

[T.R.S.]

Top Tier Citgo 93 E10. A very small station and there's only one of the four small islands where it's even available. Only 12 miles from the refinery via road so very cheap delivery cost. Almost always the cheapest 93 anywhere out of the 21 spots within 3 miles of home per GasBuddy, except when prices drop quickly. Lag in price drop for a couple days due to low sales volume, but then that delays the jumps too. Today was the first time I had to wait for one of the two pumps that dispense it to clear so I could top off.

[B58-M340iX]

BP 93 with a splash of ethanol. The 93 tests about 7% ethanol, and I add a little more ethanol to get to 15%. Gen3 M340s have a 93 AKI (US) ask on the fill door, and it'll support up to e25. I don't plan to go more than e15 until flash tunes become available.

[slilley]

Originally Posted by TimmyTurbos

It kills me every time I see someone with a nice ride filling up at WaWa or somewhere. Most people don't even know about top tier.

Wawa's corporate HQ is less than an hour away from me. I have an inside source who claims that Wawa gas follows the same Top Tier standards, but doesn't pay to belong to that group. When you consider how much gas that Wawa distrubutes on a daily basis, it makes sense that they'd want to avoid any of their stores offering poor quality gas.

I used to take all my cars to a couple local Sunoco stations that had the Top Tier rating. Then I realized that the Top Tier standard only applies to the gas, not the state of these independently-owned tanks, pumps or infrastructure.

So, I fill up a Costco when I'm passing one, but normally on the daily I fill up at Wawa. This includes track days in the Cayman.

[slilley]

Originally Posted by FrankL

So what gas and octane do you put in your BMW? I have a Marathon station close by and they sell a 90 octane no ethanol gas. I have been using 89 or 91 octane from usually Shell station.

The advice I've been given is that you shouldn't go back and forth between Ethanol and Ethanol-free gas, as it will result in moisture in the gas tank. If you always have access to higher-octane Ethanol-free gas, then that's the best possible scenario. I don't have that option where I live or drive, so I do my best to fill up with Top Tier gas. Costco is my #1 choice, but the closest one is 30 minutes away so I'm often at Wawa.

[TimmyTurbos]

Costco is Top Tier for sure. WaWa gas though dude.? That shit is slowly killing your engine. If the pumps not marked top tier, keep moving. Idc what someone in corporate tells you! They also say that burger is beef, lol.

Also avoid the small mom and pops locations or anywhere who does not have pumps clearly marked when they were last serviced..

Non top tier isn't necessarily "bad" gas, it's just not the best gas one could buy to go into a performance engine. Top tier burns cleaner etc, less gum in the works = more $ in your pocket.

[Phillies8008]

Top Tier, usually Costco or QT, highest octane they have.