MPG vs. changing weather

99gst_racer · December 19, 2011

I've only had my truck for about 6 months and I've tracked fuel economy on every tank so far. It just started getting cold here in Michigan about a 5 or 6 weeks ago. Until then, I've been averaging 16 MPG pretty consistently, which I've been content with. Once the ambient air temps dropped below 40* F, my fuel economy took a nose dive. I'm now getting 12 MPG.

Is it normal to see a 25% decrease like this? I could understand 1-2 MPG, but 4 seems ridiculous. Do you other northern folk see a fuel economy decrease like this around this time of year? I really hope it doesn't get any worse once we start approaching 0* F.

Stevens03 · December 19, 2011

Well, yes... I take a mileage hit in for the "winter" blend of fuel, so I'd say it's normal.

99gst_racer · December 19, 2011

I know it's normal to lose 'some', but is 25% normal? I've never lost 25% on any previous vehicle.

Doug_Scott · December 19, 2011

bit of a read, but has some useful info on this topic..

http://zhome.com/ZCMnL/PICS/winterGas/winterGas.html

Ajsjdjdjfjdtgg · December 19, 2011

OP. I'm also from Michigan and this will be my 2nd winter with the truck. Between auto start, winter blend fuel, longer to heat up, occasional auto 4x4 switch, and other dumb drivers I generally see a mpg loss as well. Summer - 16.5mpg. Winter - 13.5. Its not 25% but it's close. Auto start kills about 1-2 alone for me.

99gst_racer · December 19, 2011

Damn... I just had my remote start installed too. I hope I don't lose anymore MPG's than I already have. Thanks for the post.

rdnkcpa · December 19, 2011

Winter blend fuel, running a bit richer at start up, remote start can all play in to kill MPG's. Also, have you checked your tire pressure since the temperature dropped? 25% seems a little steep. How many miles on your vehicle? When was the last time you changed the air filter, plugs, & wires?

greezy · December 19, 2011

How does the remote start kill your mpg's?

This is the first truck I've had with RS and I don't see any difference in mpg's. Is it because your can just turn it on inside the house letting it warm up and that's what kill the mpg's or something else?

99gst_racer · December 19, 2011

Winter blend fuel, running a bit richer at start up, remote start can all play in to kill MPG's. Also, have you checked your tire pressure since the temperature dropped? 25% seems a little steep. How many miles on your vehicle? When was the last time you changed the air filter, plugs, & wires?

I haven't checked tire pressure since putting new tires on a couple months ago. I'll do that soon though. It has 182K on the clock. The K&N element was cleaned and oiled in July. No telling about the plugs and wires. I have a set of plugs in the garage that I'll install this week and I just ordered wires today. I doubt this stuff would make much of a difference, but it's worth trying I suppose.

99gst_racer · December 19, 2011

How does the remote start kill your mpg's?

This is the first truck I've had with RS and I don't see any difference in mpg's. Is it because your can just turn it on inside the house letting it warm up and that's what kill the mpg's or something else?

I assume it has to do with excessive run time. Mine spends a minimum of 20-30 minutes running on the RS every day this time of year. That's bound to add up to some noticable/measurable fuel comsumption throught an entire 32-gallon tank.

txab · December 19, 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

99gst_racer · December 19, 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.

00Silverado4x4 · December 19, 2011

I lose a few mpg's but I know it's all my own fault. I tend to start/idle in mornings so kids don't climb into a cold truck. Also idle throughout the day more often such as after lunch before going back to work. Of course if you don't do anything like that I'd say winter gas blend, double check your tire psi as everyone has said.

waumo1 · December 20, 2011

Mine spends a minimum of 20-30 minutes running on the RS every day this time of year. That's bound to add up to some noticable/measurable fuel comsumption throught an entire 32-gallon tank.

There is your answer. Idling cold for 20-30 minutes a day, plus cold weather driving, plus winter blend gas....

Ajsjdjdjfjdtgg · December 20, 2011

Mine spends a minimum of 20-30 minutes running on the RS every day this time of year. That's bound to add up to some noticable/measurable fuel comsumption throught an entire 32-gallon tank.

There is your answer. Idling cold for 20-30 minutes a day, plus cold weather driving, plus winter blend gas....

yea, i let mine run for 10-15 so that may explain that extra 1mpg worse youre getting than me. id rather pay an extra $10 in gas a month and have a warm car though, so its worth it.