I'm about 2 1/2 years and 9,000 miles into ownership of my first Porsche, an '09 C2 6MT. "Gretchen" is now at 44,000 miles. She runs well and is up to date on service including new spark plugs less than 5K miles ago. A real delight to drive but a small concern is fuel mileage is on the low side - about 18-19 mpg for mixed driving. I try to get her out on open roads occasionally to let the reins loose, and then get about 22 mpg. I use Shell V Power almost exclusively. The two oil samples (posted on another thread) I've done show about 2% fuel in the oil. Wear metal readings are fine.

So my question is: Would it be worth taking the car into local Porsche dealership service for a checkup? Say like maybe there's a DME update that car hasn't gotten? I'm third owner, and to my knowledge car hasn't seen Porsche dealership since about first year.

 

Hello there,

FWIW - I have a 2010 C2S 6MT CAB with ~ 48K miles. I've not changed my spark plugs yet and I get essentially the same mpg (18-19mpg) for mixed driving. Though I will admit, I run it over 85mph often when on interstate. I'm sure I could get over 20mpg if I drive efficiently like my wife (aka no fun boring style & short shift often).

IMHO - I'd stay away from dealer and find a reputable independent to get a "check-up" if you're so inclined...

Good luck!

 

Recent thread where folks share their mpg: https://rennlist.com/forums/997-foru...r-avg-mpg.html

I get about 18mpg and I drive spirited once warmed up, always B Roads, almost never highway, some around town. I can't speak for the fuel in oil %.

 

Thanks for the link - I should've searched first before posting. Many reports of similar mileage so I'm in the ballpark it appears.

 

Odd - I average 22mpg almost exclusively driven in rush hour or hard on back roads. My car is about to hit 100k miles too.

 

If your car is running well and maintenance items are up to date, there is no reason whatsoever to get anywhere near a dealership. The SAs start to salivate when they see a victim, I mean customer, walk through the door asking them to look over their car.

 

I wish I got 18mpg :-) I guess my foot is too heavy.

 

i get 16-18 mpg, mostly LA street driving. Doesn't sound unusual.

 

No s**t. And I don't have the faintest idea of what the % of oil is in my fuel. Never heard of this concern before. Is it something that many of you have checked on a regular basis?

 

So jealous, I get 16 mpg city driving. Heavy foot. I suggest a steady 65mpg and reset the indicator and see what you average. I can get mid 20s doing that until I loose my mind and hot it.

 

Fuel in the oil thins out the viscosity. I think it's common to DI engines nowadays but if severe (say 5% or more) it can indicate mechanical problems. Ford's Ecoboost engines are notorious for fuel dilution. In my case I think the small amount of fuel showing is from infrequent driving and the DI engine. I'll just keep an eye on it and stick with 3-4K OCI. Car runs great and there's no other problems showing in the oil samples so far.

 

You're correct. Noted.

 

I'm not sure of the importance but it's part of a Blackstone report. Mine is s a consistent .5% and the universal average is anything less than 2%.
This is over many years and a car with almost 100k miles.