Jukelemon

I recall getting VERY good gas mileage in my last 993 i.e. solid 20's for all around driving in town/hwy. On hwy only, I was getting mid 20's.

On this 993, I cannot get over the high teens. What gives?

Thx

g_murray

Try not to 'lollygag' in 3rd. gear so much ...and use 6th. gear a lot more (instead of 4th.) when you're on the highway.

Gerry

(Averaging a solid 24mpg since I got the car almost 2 yrs. ago.)

RallyJon

Once the gas changed for winter, my mileage dropped from ~19 to ~15. All suburban/back roads. Most days, I don't get past 4th gear at all.

Jukelemon

I dont lollygag at all when I am driving in the city. I am always changing the gears to higher gears.

I am going to replace the plugs, rotor cap and see what kind of difference that makes. In my past experience, unless the plugs are just plain foul, it will not make that much difference. And by the idle/general performance of the engine, I doubt that is the case. BUT they need changing anyway.

Thanks all

jnnking

Just as a reference point, I got 19 pretty consistent all summer. I work from home, but it's my daily driver.

gerrard128

Was getting 18-19 when I first got the car in Dec 06. Had it serviced last month and MPG has increased steadily, averaging 26 on motorways and 20 around town since. New plugs might help?

TomF

Same with the rotten gas we have here in Seattle. When they up the Ethanol content for winter, my mileage drops by about 4 mpg. I am a very conservative driver IMHO, and really keep my foot out of it... most of the time! I get about 18 in the summer and about 14 in the winter months. The ethanol content of the gas is huge here in the winter. Not to mention the fact that we are lucky if we get better than 91 octane.

TRINITONY

Wear lighter shoes...

Just kidding..gl..let us know your findings..

Ed Burdell

If you drive it properly, your gas mileage is supposed to suck, correct?

The Brewmeister

Mileage drops with the temperature. Richer running, longer warm-ups add up
to lower mileage.

JasonAndreas

Usually poor mileage is a sign of an impending O2 sensor failure.

black ice

Second the o2 sensor issue. they start going after 50-70K. 95s have one I think, 96 and later has like four of them.

tj90

Good point on the higher ethanol content of winter gas. All my vehicles loose MPG in the winter. As far as the O2 sensors - If you have a 95, you only have one. In a few minutes you can visually inspect it. If its heavily carboned, replace it. If you have a 96+ I understand that you only need to replace the upstream left and right banks. These provide the feedback loops to control fuel trim. The downstream ones monitor cat efficency (pollution) and only throw an MIL light not affecting MPG. Your downstream O2s should never be carboned if your cats are working properly. At ~$100 each for the O2s, be careful blindly replacing these parts unless you are convinced there toast!

RallyJon

I replaced the (one) O2 sensor in the Fall, after it threw a couple of codes foreshadowing doom. Mileage still sucks.

richardew

I've consistently been getting 23-23 mpg on the highway, 16-18 in the city. When driven aggressively, I haven't noticed any drop-off in gas mileage. Even though the car is less aerodynamic with the top down, I haven't noticed any drop in gas mileage there either. Most of my driving has been on the highway, and I don't sit in sixth with the cruise control. I avoid any heavy throttle inputs at less than 4000 rpms. Maybe things will change once the car is broken in. I have only been driving it for 10 years, 186,000+ miles.
rich
96 C4 Cab
Iris Blue/Marble/Marble