OT - 2001 Chevy K1500 Fuel Mileage?

charles todd · Feb 10, 2011

I have noticed it seems like my 2001 Chevy K1500 fuel consumption has increased. I have 145,000 miles and no check engine lights or rough running. I use synthetic oils from bumper-to-bumper, have a K&N Cold Air intake system and the plugs have less than 20,000 on them. Over the years the mileage has gone from 16mpg to 12-13mpg, maybe 14mpg if I drive easy. I have not really changed my driving habits.

Could I actually have a problem or is it the Ethanol the fuel companies are blending into our fuels? I am suspecting the Ethanol. Our 2008 Mini Cooper S has also went from 35-33mpg to 30-31mpg with less than 60,000 miles. Thoughts?

CT

toolman · Feb 10, 2011

I don,t really know , winter conditions can reduce mileage as well but i,m wondering the same as you about this Ethanol as i,m seeing lower mileage in both my Chevy and Ford lately.

BradWi · Feb 10, 2011

I have an 03 2500 and have the same issue.When i got it it stayed around 12 in town and 14 to 16 on highway.now i'm lucky to keep 10 as an average 13 on the highway.On a sidenote we have had a ton of problems with the ethanol blended fuel.It has a short tank life and our chainsaws and other two stroke engines don't like it.alot of times they don't start or run crappy,I cleaned out the carbs on all that stuff thinking it was a krud problem.Then i started using recreational fuel(no ethanol)and haven't had a problem since

JMS/.MN · Feb 10, 2011

Ethanol does have a lower energy level than straight gasoline, so any ethanol mix will drop your mileage. We have an 03 Dodge van, E85 capable. Our gas has had 10% ethanol for decades, so when we switch to E85, our mileage drops about 11% below using the E10. BUT, E85 is currently about 65 cents per gallon cheaper than standard E10, so it is well worth using. The math simply works out, and there is no danger of gas line freezing- we don"t use additives anymore. Even at 40 cents cheaper, we are money ahead. Also, winter mileage is going to be lower in cold areas- engine warm-ups, excessive idling, etc.

MarkB_MI · Feb 11, 2011

There isn't that much more ethanol in gas today than there was, say, 5 years ago. More likely your truck's engine is getting a little tired. As for the mileage on the Mini, that's about a ten percent drop which isn't that much and could be due just to driving habits.

Is your torque converter locking up? If not, that can hurt your highway mileage.

Have you put larger tires on the truck? That can make it appear as though your mileage is worse.

Have you changed the exhaust system? Aftermarket mufflers can be very bad for mileage.

You mention the K&N intake. If the mileage got worse after installing it, maybe you should try putting the factory intake back on.

Allan in NE · Feb 11, 2011

Hi Charles,

Is that lower front air dam still intact and in place?

That plastic joker has a great deal to do with mileage.

Allan

charles todd · Feb 11, 2011

Allan, you are usually "spot on" when you figure something out. Actually it has been laying by my shed since last winter. It was removed by terra firma one day. I thought about that too. Does that front air dam divert that much air? If it warms up this weekend I'll replace it back onto the bumper.

As for tires, it had 245/75 R16 stock, I had 285/75 R16 for years (spedo corrected) and recently installed 265/75 R16 (have not corrected the spedo but know the multiplier to factor offset. The K&N and the glass pack muffler have not been an issue as of now. I could get 13 city/16 hwy with full lug tires. Now with smaller tires (and no air dam) I am about 10 city/13 hwy or worse. I was just wondering if at 150,000 miles if the O2 sensors needed changed? Or something?

CT

Rick Kr · Feb 11, 2011

Charles,

I know you are correcting your speedo. For what its worth, when i went from 265s to 285s I lost 3 mpg. That is with the speedo corrected.

I believe tread pattern had the most effect. Went from P series hi way tires, to LT 10 ply truck tires that hum nice and loud on the expressway.

Bad move on my part. Especially on my daily driver.

Rick

buickanddeere · Feb 11, 2011

O2 sensors gradually fail with age and run the engine over rich.
Cat convertors can plug and cause back pressure.

Allan in NE · Feb 11, 2011

Dunno,

Sure can't speak to your Chevy, but I have a bad history of knockin' those goofy things off in the winter with the drifts out in this country.

When I bought this last Ford, the first thing they told me was that it would make a 3mpg difference if it was missing. This was gleaned from their new-model training classes.

The one on this truck is about 8" deep tho.......

Allan

LenND · Feb 11, 2011

Up in this country a lot drivers complain about lower gas mileage. BUT in colder temps you will never get same mileage. For one thing most people warm their vehicle up a little and you would be surprized how much extra gas that takes out of a tank full.

charles todd · Feb 12, 2011

I'm adding up the recent changes. I went from a 285/75 R16 (33") 8 ply aggressive all-terrain DOWN to a 265/75 R16 (31.5?") 10 ply full lug tire (nice highway hum and I don't get stuck). Shortly after I "accidentally removed" the lower bumper air dam... Maybe its not O2 sensors or Ethanol after all. Maybe I'm really getting 12 mpg right now :shock:

CT

OT - 2001 Chevy K1500 Fuel Mileage?

charles todd

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toolman

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BradWi

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JMS/.MN

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MarkB_MI

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Allan in NE

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charles todd

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Rick Kr

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Allan in NE

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