The visible end of my GS300 AWD exhaust pipes are extremely sooty, always have been this way, the car does not burn oil, maybe 0.5 qt per 5000 miles, at the most.

At 20,000 miles, the dealer cleaned my injectors and filters and suggested I use regular gas instead of the Premium gas I had been using. The soot is still there, power dropped a bit, but noticeable only when the engine is lugging.


However, by switching to regular as the dealer suggested, the gas mileage increased by a couple mpg. Four thousnad miles later it is still better than before. Go figure!

Anyone have a similar problem, and if so, are you concerned or did you do somthing about it?

/Nick

 

ummmmm....doesnt the owner manual and gas cap recommend premium....and i'm surprised that the dealer recommended regular gas for the 3gs...i'll never put anything less than premium and cali already only have 91 oct while in fl i was using 93....

not sure about the additional miles, you do have proof so if it works for ya...who knows, hahaha, but 100% all the time for my toy, since going reg in my older toys, civics and prelude, produces knocking noise in the engine...

 

Both our 2Is350 and 3gs have same black Soot, asked my service writer if there was anything they could do about it, - No. So is this contributed to octane or timing?