BMW 328i filled with regular unleaded

[CheesyRider]

So, I got my shiny new bike recently. Then, my wife started talking about getting a used BMW car. Long story short, I caved and she got her BMW. The car ran great until she accidentally put in regular unleaded instead of premium. Shortly thereafter she got a cylinder misfire engine code. After checking around on BMW car forums, it seems BMWs can be quite sensitive to low octane gas and it isn't uncommon to get a check engine light if premium isn't used. Her tank is 3/4 full right now.

Now my question. Would the best way to raise the octane be to put in 1/4 tank of 110 octane racing gas, or to us an octane booster? If an octane booster is the way to go, what brand?

Thanks!!

[Fla_rider]

Royal Purple Max Octane Booster!

http://www.motoiq.com/MagazineArticl...e-Booster.aspx

[jkelley]

Most octane boosters are snake oil and will only raise octane tenths of a point if any! Nothing magical can be had from a can, depending on tank size etc. will dictate your dilution percentage on any product used.

[CheesyRider]

Royal Purple Max Octane Booster!

http://www.motoiq.com/MagazineArticl...e-Booster.aspx

Thanks! It looks like the auto parts store near us carries it. There's one thing I almost forgot about. When my wife brought the car to AutoZone to have the check engine light read, the guy told her to dump in a can of Seaform. So, she put dumped a can of Seafoam into the tank. It seems idiotic as I don't think Seafoam makes any claims about boosting octane. Would it be okay to add the Royal Purple even though the Seafoam is already in there? I'm concerned too many additives might mess something up.

[CheesyRider]

Most octane boosters are snake oil and will only raise octane tenths of a point if any! Nothing magical can be had from a can, depending on tank size etc. will dictate your dilution percentage on any product used.

So, your opinion would be to use the racing fuel to raise the octane?

[Steve 0080]

+1 on air plane fuel or what ever the label is...SeaFoam will not hurt...may help as well..... I am not real sure the problems fuel/low octane....seems to me that a lot of vehicles call for hi fuel...but doubt you would be left on the sides of the road if no hi/oct was available....JMHO

[1BADF6B]

So, I got my shiny new bike recently. Then, my wife started talking about getting a used BMW car. Long story short, I caved and she got her BMW. The car ran great until she accidentally put in regular unleaded instead of premium. Shortly thereafter she got a cylinder misfire engine code. After checking around on BMW car forums, it seems BMWs can be quite sensitive to low octane gas and it isn't uncommon to get a check engine light if premium isn't used. Her tank is 3/4 full right now.



Now my question. Would the best way to raise the octane be to put in 1/4 tank of 110 octane racing gas, or to us an octane booster? If an octane booster is the way to go, what brand?

Thanks!!

Top off the tank with premium and before you do dump a bottle of 108 octane booster. Seafoam is a tune up in a bottle but I prefer star tron. Best of luck to you.

[bigbird]

+1 on air plane fuel or what ever the label is...

Careful on that. Av gas is 130 octane, fortified with lead AFAIK.
You do not want tetraethyl lead poisoning the cat converter and O2 sensors.

[jkelley]

So, your opinion would be to use the racing fuel to raise the octane?

Personally I would ride it out to below 1/4 tank and then put 93 in it, but if you are so inclined to use racing fuel knowing the tank size you could probably get pretty close to the proper mix.?.?

[CheesyRider]

Thanks for the advice everyone. My wife just called from the gas station. She was going to put the 110 octane in the tank, but the nozzle was too big. Instead, she topped off with non-ethanol premium.

It just occurred to me that if the check engine light comes back on, I can siphon the gas and put it in my van. Then I can fill her tank completely with premium fuel. Luckily, the car is under warranty. So, if it turns out it was a just a coincidence that the check engine light came on with regular unleaded fuel, we shouldn't have to pay for a repair.