[GrandTour]

Just went to my first HPDE track experience on June 4/5th. Only problem was I apparently had a stroke b/c I accidentally pumped 110 LEADED racing fuel into my ‘20 440i!! As a track newbie I’d asked another driver where to refuel some 93, and he said “middle pump at the station right outside the gate - it’s only $4.83/gal”. I pulled in with less than 1/4 tank left, saw the 93 octane tag and started refueling. The price window said 9.99 so I figured the indicator was broken. After pumping less than half a tank the price meter said $70 so I stopped pumping and I was like, something fishy there! Drove 3 more 5-lap sessions (about 40 miles). Went back for more gas next day and pumped another 4 gallons in till I finally noticed that the nozzle I pulled was actually “110 octane leaded racing”. It was right next to the 93. Never knew a leaded nozzle would fit my fuel port!! Drove back to the track and BMW techs said DON’T DRIVE YOUR CAR dude! Long story short: flat-bedded it 150 miles to dealer, they drained/refilled the tank, and I’ve driven 200 miles since with no issues.

[n55david]

LOL

You may wanna order new 02 sensors.. well at least the primary pre-cat 02.. your engine is fine but the lead basically fucks the sensors up. At the very least the values the sensors see are now off. It may not be enough to cause a problem but hard to know. If it was me I'd swap it.

[thejeremyman9]

At least he probably had clean timing

[Billfitz]

Lead destroys CATs. That won't show up after one day. With continued use it would eventually show up as a failed emissions test should your state require them.

[n55david]

Originally Posted by Billfitz

Lead destroys CATs. That won't show up after one day. With continued use it would eventually show up as a failed emissions test should your state require them.

Yeah that too

[GrandTour]

Thanks. I figured if I wasn’t throwing any codes everything was basically still running in spec - keeping my fingers crossed! Thought about trying to get someone besides a dealer to siphon it, but I’ve got saddle tanks etc. and figured the least of 2 evils was just fess up to the dealer and have them clean it right: better to maybe void the warranty but save the CAT, than void the warranty AND maybe having to spring for a new CAT and sensors!

[5mall5nail5]

You'll be fine. Prolonged use will foul sensors. Some sensors are even leaded fuel safe. No bigs.