MPG vs. changing weather

Rons05z71 · December 20, 2011

If you over oiled the air filter you might need to clean the MAF. You can get MAF cleaner at any autoparts store.

wurgs · December 20, 2011

According to your posts, you changed tires about the same time as your mpg change. Some tires offer more rolling resistance than others. This could be 1 factor. Winter blend fuel, colder air and engine warm-up are other factors

Correct. But if I remember correctly, I did put a few tanks of fuel through it on the new tires before it got cold, and I was still getting my 16 MPG. I replaced my worn A/T tires with new A/T tires, so I didn't expect to lose any fuel economy from the tire change.

If you didn't put the same tires back on it might make a difference. Tire weight and compostion will make a difference. When I went from stock Duelers to BFG ATs my mileage went down over 1 mpg.

Ryan00TJ · December 20, 2011

I drive the same route to work everyday. Over the summer months I average 19.3 to 19.7mpg usually per tank. Since winter blend fuel and colder temps have hit I now average 17.5 to 18mpg this past month. Driving to my old job, all city 35mph stoplight to stoplight I would average 14.7 to 15.5mpg summer and 12.8 to 14mpg winter.

99gst_racer · December 20, 2011

I just filled up yesterday and calculated it at 10.9 MPG now that I'm using my remote start twice every day.

So, it seems I've lost 4 MPG from the weather and winter fuel, and another 1 MPG for the RS. This sucks.

jro909 · January 4, 2012

i lost maybe 1-2 mpg...70 bucks worth of gas will last me easily a week clocking 30 miles or so a day...its currently 25 degrees F outside..i also allow my truck to warm up until it idles down and goes into close loop before i drive it in the winter..winter fuel does play a factor, along with 4x4 and other things but not enough to hit the % you stated unless your driving it hard or having alot of weight in it....or if you have an underlying problem

also on a side note i know i read on here an article somebody posted on how fuel filters really don't effect mpg clogged or not

04SILVRADO · January 5, 2012

It's the winter blend gas!!! I'm around 17 to 18 mpgs in the warmer months.. My last tank was @ 15.1 mpg's...

Wires · January 21, 2012

Stupid question, but if you have a vehicle that accepts E85, does it suffer as bad in the winter as well (with regular fuel)? Just wondering if it can compensate for the extra methonal. I seem to take a 10% hit in fuel economy during the winter as well.

99gst_racer · February 15, 2012

Well, a bit of a follow-up. I recently starting throwing the P0171 and P0174 CEL, which pointed to a possible vacuum leak. So, I spent yesterday afternoon replacing the intake manifold gaskets, injector o-rings, throttle body seal, and double checking all vacuum lines. After driving it today, I can already tell it is running better and my low RPM, light throttle response is greatly improved. So, I'll top off my gas tank today and I'll see if fuel economy improves. I'm expecting it to bump back up to 13-14 mpg, where it should be on winter gas. I'll update in a week or so.

99gst_racer · June 12, 2012

Another follow-up; Since my last update, I've changed all of my drivetrain fluids, ran a bottle of Lucas injecter cleaner through the gas, and installed a K&N FIPK intake kit. We're back on summer blend now and I've cycled several tanks of fuel. I'm consistantly getting 14 mpg. So, I'm exactly 2 mpg short from last summer, and I was running the A/C all last summer too.

I'm running out of options here. The ECU/tune is one of the few things that I haven't messed with. Is it possible to take my truck to a dealership and have the ECU "reflashed"? And is it possible to pick up 2 mpg from a reflashing? Is there a better alternative to reflashing?