Gas Mileage

[Marion Van Hal]

My gas MPG has droped to 12-13 mpg with strictley town driving with my 2002 3800 v6 Buick LeSaber. It is in the cold IA weather. What could my problem be? Should I get the 17MPG? Thanks

[vgames33]

If you went from some highway in warm weather to all city in the cold, then its believeable. Until your car warms up, you are in craptastic MPG mode (otherwise known as open loop), which helps everything warm up faster.

Your tires may also need more air since its cold outside. I'd also look into a tune up and air filter change, since the car is 6 years old. How many miles are on your car?

[Marion Van Hal]

I carry 36 lbs in the tires. [New tires]The filter should have been checked the last I had it serviced but will check it. There is 63,000 Miles on the car.
The last tank has been all small town driving ar 12-13 MPG. I hope to get it out on the road again befor long. I got around 24 MPG on the last 2000 mile trip. Was also somewhat cold then.
Thanks Marion

[j cAT]

Originally Posted by Marion Van Hal

My gas MPG has droped to 12-13 mpg with strictley town driving with my 2002 3800 v6 Buick LeSaber. It is in the cold IA weather. What could my problem be? Should I get the 17MPG? Thanks

short trip driving in very cold weather less than 30deg f will cause a huge drop in mileage......sudden drops in temp you have to check tire pressures as they will drop considerably.....in warm weather 24mpg is normal at 60-70mph.... at 90-100mph it will drop to 20mpg........

[curtis73]

Really cold air is very dense, and can cause more gasoline to fall out of suspension. As a response to that the EFI injects more fuel. Combine that with the fact that winter blended fuel is up to 15% ethanol (which has less energy and density) and mileage can go in the dumpster.

[Autopro1962]

A new fuel filter can help I replaced a lot with 30000 miles that are pluged solid and if you are letting it warm up that also will effect MPG.

[Marion Van Hal]

Correction on milage. The Buick has 67,000 miles on it. I just checked the tires. They have 35 lbs pressure but it is a little warmer today. [24 degrees] It hasn't been much above 10 degrees for a couple weeks.
Thanks again.

[j cAT]

Originally Posted by Autopro1962

A new fuel filter can help I replaced a lot with 30000 miles that are pluged solid and if you are letting it warm up that also will effect MPG.

fuel filter replacement will not improve gas mileage..........but if your fuel filter was plugged it will make you fuel pump happy...........

[Autopro1962]

Originally Posted by j cAT

fuel filter replacement will not improve gas mileage..........but if your fuel filter was plugged it will make you fuel pump happy...........

WOW!CLUELESS

[UncleBob]

if a filter is 100% clogged, the car won't even run autopro

If its clogged enough to reduce supply to less than the demand, it will at the very least, cause the AFR to go lean at high demand and/or cause it to misfire and stumble under high load.

You could definitely argue that worsens the mileage, but so does disconnecting 4 spark plugs, or any number of mechanical problems you can throw on the table. Its a runnability problem at that point, not just a mileage issue

[Autopro1962]

Hey!All I'm saying is check your basic maintenance items,air filter,fuel filter,tire pressure,if the check eng or service eng light is not on that probaly all your going to get MPG,you could try to use reg.unleaded.

[Marion Van Hal]

Thanks to all for the advise.
Marion

[fredjacksonsan]

After trying all those things, head back out on the highway for a bit to see what your mileage is. If it's not back up to where you'd expect it, then let us know.

[Marion Van Hal]

Originally Posted by fredjacksonsan

After trying all those things, head back out on the highway for a bit to see what your mileage is. If it's not back up to where you'd expect it, then let us know.

I finally got back on the highway after helping my wife while healing from a broken hip.
On a 100 MI. drive I got 27.4 mpg. On mixed driving I got around 20 mpg.
Includes a couple drives of 32 and 100 mi. The cold weather and the all town driving must have been most of the cause for the 12-13 mpg.
Thanks Marion

[j cAT]

Originally Posted by Marion Van Hal

I finally got back on the highway after helping my wife while healing from a broken hip.
On a 100 MI. drive I got 27.4 mpg. On mixed driving I got around 20 mpg.
Includes a couple drives of 32 and 100 mi. The cold weather and the all town driving must have been most of the cause for the 12-13 mpg.
Thanks Marion

that mpg looks normal...so your vehicle is running very good still at 70,000mi...

if you haven't , change the fuel filter every 30-40,000mi. this will keep your engine and fuel pump from problems..