08-19-04, 05:49 PM
My 1994 Concours seems to only get 13.1-13.7 mpg around town with the A/C on. What could be causing such low mpg? I just changed the oil and filter (10W-30), changed PCV valve, fresh coolant and hoses, changed my trans. solenoids. I thought that the mileage would improve with it now shifting in all of the gears but it didn't help much.
No codes are coming up. I see no visible fuel leaks and the engine runs very smoothly. Any info would be appreciated.
08-19-04, 10:59 PM
I'll bet it goes up again around October-November timeframe. I'm almost willing to bet it's good old reformulated gasoline, AKA "summer blend" gas. Higher alcohol contents, use of MTBE or (please say it isn't so) methanol, etc. all contribute to lower gas mileage. It's the same volume of gasoline in the tank, but it takes more of it to get the correct air/fuel ratio with all the EPA-mandated goodies in there, so your mileage will drop. What was it in the April-May timeframe?
08-20-04, 02:58 PM
There are two major factors concerning gas mileage. 1) vehicle and condition 2) driver.
You should be able to improve the mileage. You didn't indicate mileage on it but it might be worth new plugs.
Driving style has a big effect. I am a somewhat fast driver but I try to be smooth and anticipate traffic and lights. Being smooth and steady on the gas makes a big difference.
08-20-04, 04:23 PM
Definitely not my driving style. I drive fairly low speeds on the road and don't gun it etc. Very smooth. It has just over 100K on it. The plugs look good but I am not sure when they were last changed. I wouldn't think that the plugs would cause it to drop to 13 or so. It has been at 13 every since I have owned it. (month or so) They are auto lite platinums. I will replace them in the next week or so. I just wanted to see if anything else might cause it. Thanks.
08-21-04, 01:25 AM
13 is not bad for short trips in town it is a Cadillac.
I have a 95 Seville with 86000 miles and drive 3 miles to work one way in stop and go traffic. My average is 13 to 14 mpg unless I add some freeway action then I go up to 17 mpg no complaints here. On my last road trip I did get 22 mpg on the highway with speeds that exceeded the speed limit.
08-21-04, 11:49 AM
I guess I forgot: 3) type of driving.
Short trips really hurt gas mileage!