Very low mpg, help plz

[BIGJake111]

These cars can get anywhere from great mileage to low. If you are in 6th on the highway and mostly doing highway driving the mileage should be better than 16 though. I notice a significant difference when going from city to highway driving in the boxster, a much larger difference then any other cars i drive.

How are you factoring the mpg? Does your car have a computer or are you figuring your mpg manually?

[Mike689]

Originally Posted by BIGJake111

These cars can get anywhere from great mileage to low. If you are in 6th on the highway and mostly doing highway driving the mileage should be better than 16 though. I notice a significant difference when going from city to highway driving in the boxster, a much larger difference then any other cars i drive.

How are you factoring the mpg? Does your car have a computer or are you figuring your mpg manually?

I've been doing it manually. Even with city driving I don't think it should be 16mpg.

[911monty]

Mike; Are you smelling fuel around your car? Any leaks? You should have a CEL lit if that much fuel is being unburnt in the engine and your Cats should be glowing red! Why are you shifting at 3.2k strange engine noises? I would wonder if an exhaust valve is stuck open, but like I say your cats would not like it. NOT those cats!

[Mike689]

Lol I don't have 93 in my area and I think CA it doesn't go over 91. It shouldn't matter though because the engine has the octane knock sensor thing right?