Tief Lernen

12,000 miles on my 718 Boxster S. Recently did a HPDE event. As the sun was setting in the evening I noticed a very obvious red residue inside the exhaust pipes. Has anyone else seen this?

I always run Top Tier gas, 91 octane, mostly Chevron.

It is definitely the color of rust. Maybe it's brake dust getting ingested and then forming iron oxide with the water from combustion?

Tief Lernen

wriggly

85Gold

spdracerut

That's bizarre...... Do you do a lot of short drives? In that case, water could condensate in the exhaust and not burn off. I've seen that red tint from race fuel and octane boosters too.

Greg Fishman

Did you buy gas at the track?

modifieda4

my guess is that the red is from additives in the fuel + high exhaust temps.

Tief Lernen

I never take short trips with this car. Did not get fuel at the track.