I have about 5,200 km on 8. I notice heavy carbon deposits at the exhaust. I know the car runs rich, but is this normal? It gets lots of highway miles incidently.

TIA

 

Try a search on "smoot" :D

S

 

It's "normal".

 

From a few threads and experience, I run a lower octane fuel and this has disappeared.

Andrew

 

its not just caus eth ecar runs rich. in fact if you drive around without go over certain rpms or throttle positions "like driving on the highway alot in your case) it is almost all from burning oil.

in closed loop the car does a good job at staying at or close to 14.1 afr. that is hardly rich.