justinmm2

I've been noticing for a little while now that my mileage has been getting worse and worse. At first I chalked it up to leadfooting it a little bit more and then using the AC, and more city driving, but I'm nearly out of gas on my current tank and I'm in the 180s. My "E" light will probably blip on while I'm driving home. I think my last tank was something like 12.9 gallons which took me 201 miles. That's 15-16mpg. The last few tanks have been comparable, slightly better/worse, but not much.

I read something about C4s having a recall on the meters, but given that I'm looking at fuel consumption, that obviously shouldn't apply. Plus, I have a C2 My tire pressures should be good (I'll double-check).

Could it be foul plugs? What should I be on the lookout for?

Justin

an02boxster

I run a/c constantly year round, make no effort to save fuel in town or on highway. Forget to shift into fifth or sixth all too often. Car is fun to drive why would I try to save fuel that, IS NO FUN. Consistantly I get 21-22 mpg.

Also, I'm driving four wheels. Sounds like you might have something wrong.

Good luck with that.

996 Convert

I get 13-14 consistently around town.

delirium

I get worse mileage when the weather gets warm... maybe same for you?

LVDell

Nothing wrong at all. Comes down to conditions, driving style, etc.

Perosonally I get about 225 a tank. Which is roughly 14-15mpg. I personally find it a far stretch that some people are claiming 22mpg which comes to about 350-375 miles a tank which is IMPOSSIBLE! Are you guys that claim 22mpg actually calculating your mpg properly???

I just drive it and when the amber light comes on I fill it up. Simple as that!

FYI.....IIRC our cars were rated at something like 16/24 when released which we all know EPA numbers are already inflated.

996 Convert

Ditto. However, a few months ago, I got a ticket right after filling up so I drove like a little old lady the rest of the way home on the highway. My computer registered 29 MPG over the course of about one and a half hours of driving!

justinmm2

Dell,

One reason I'm so suspicious is because I was getting closer to 19-22mpg when I first got the car, only a few months ago. I'd calculate it by dividing the amount I put in by the the trip calculator mileage. I'd regularly drive 250ish on 12.5 gallons or so (I usually filled up just south of the 1/4 tank). Now I'm getting 200 on 13 gallons regularly, or 215 on 14 gallons. Given that I've spent over $300 on gas this month (so far), I'm eager to figure it out. Who knows - maybe there's more HP in there, too!

Justin

996 Convert

Not to mention most of us probably have much heavier feet than the average joe out there.

LVDell

There's your problem. People it is simple. Wanna see what kind of gas mileage you are getting? Do the simple way with pencil and paper. Run that tank down as low as you can. Set the odometer to 0, fill it up, drive as normal (not trying to get the best gas consumption as possible) and then when you drive till you get back down to as low as you can get, then go fill it up to the top (same as last fill up), then divide your odometer by the gallons pumped in. I think you will find very quickly that reality is much different that what you thought.

996 Convert

I thought computers were always accurate! Actually, that was only one particular instance and since I didn't drain the tank, I couldn't tell you what the real mileage would have been. However, my 13-14 consistently on the computer is pretty accurate using your method. I usually fill about 14 gallons and get right around 200 miles.

smshirk

On interstate driving 70 to 90, but keeping fairly contstant in upper 70s except to pass, I get 20 to 22 consisitently. Around town from 15 to 18. I check it the old fashioned way every time I fill it up for 40k miles. It dropped significantly for a 3 or 4 week period earliier this year. It turned out that my tire pressure had dropped to mid 30s on rears and low 30s in front. No idea how it happened, especially since they were uniform. After re inflation the mileage went back to where it has always been.

Hootchi

I get about the same mileage....its worse than my previous M5 with a V8....about 15MPG....I know...its brutal.

Riad

I should just have a gas tanker truck follow me around so I can refuel on the road.

However, if I'm taking a long trip and put the cruise control on I get very good gas mileage.

Eric - Plug Guy

In town, summer heat, 17mpg. Highway is higher, but I get about 190 miles city driving before I need to fill, and I do NOT let it get to 'empty'....

fast1

I thought computers were always accurate!

They are accurate but they merely give you a snapshot in time. The only accurate way to determine your average MPG is to do what Dell recommends. Make certain that your gas tank is full on your next fillup and then on your following trip to the gas station, simply divide the gallons of gas you pump into your tank into the miles driven. After you do this a few times you'll have a real good idea of what your car's real MPG is.