Bad MPG?

CarsonF · August 27, 2021

I have a 2017 Silverado 1500. I put a 3 inch level on the front and i’m running 20 x 12 wheels and 33 x 12.5 MT tires. I’ve noticed my gas mileage has gotten worse over the past couple days and I’m not sure why. I was used to getting around 15 and it’s been creeping down into the low 13’s. Does any one have any ideas why? Also what’s your setup and what MPG do you get? (I know it’s a truck it won’t get good gas mileage but with the price of gas right now every mile counts)

asilverblazer · August 27, 2021

Larger, heavier tires, plus worse aerodynamics = less mpg.

rav3 · August 27, 2021

Tire diameters are larger, which results in lower RPM's, wouldn't that lower miles that you gas mileage is calculated from. Just a guess on my part. Don't they need to change something that runs the speedo to correct for that? Just a wild guess on my part.

Silverado4x4 · August 27, 2021

3 hours ago, CarsonF said:

I have a 2017 Silverado 1500. I put a 3 inch level on the front and i’m running 20 x 12 wheels and 33 x 12.5 MT tires. I’ve noticed my gas mileage has gotten worse over the past couple days and I’m not sure why. I was used to getting around 15 and it’s been creeping down into the low 13’s. Does any one have any ideas why? Also what’s your setup and what MPG do you get? (I know it’s a truck it won’t get good gas mileage but with the price of gas right now every mile counts)

The leveling kit raised the front knocking your aerodynamics down then adding larger and heavier tires kills MPG also M/T tires have a far more less rolling resistance then your other tires again kills MPG which means the truck has to work harder to keep it rolling and taking off from a stop.

JimCost2014 · August 27, 2021

10 hours ago, CarsonF said:

I have a 2017 Silverado 1500. I put a 3 inch level on the front and i’m running 20 x 12 wheels and 33 x 12.5 MT tires. I’ve noticed my gas mileage has gotten worse over the past couple days and I’m not sure why. I was used to getting around 15 and it’s been creeping down into the low 13’s. Does any one have any ideas why? Also what’s your setup and what MPG do you get? (I know it’s a truck it won’t get good gas mileage but with the price of gas right now every mile counts)

Welcome to the site.

So, to be clear, your mileage has decreased since the lift was installed, where you started at (15 MPG), now down to (13 MPG)?

How many mile on the truck? Changed gas station, different route to work, just all the standard questions...

Edited August 28, 2021 by JimCost2014

MikeBMW · August 27, 2021

9 hours ago, CarsonF said:

I have a 2017 Silverado 1500. I put a 3 inch level on the front and i’m running 20 x 12 wheels and 33 x 12.5 MT tires. I’ve noticed my gas mileage has gotten worse over the past couple days and I’m not sure why. I was used to getting around 15 and it’s been creeping down into the low 13’s. Does any one have any ideas why? Also what’s your setup and what MPG do you get? (I know it’s a truck it won’t get good gas mileage but with the price of gas right now every mile counts)

You're doing OK. With my level (and other lift items) with 35X12.5 tires, I'm lucky to get 10 MPGs around town.

Edited August 27, 2021 by MikeBMW

JimCost2014 · August 28, 2021

1 hour ago, MikeBMW said:

You're doing OK. With my level (and other lift items) with 35X12.5 tires, I'm lucky to get 10 MPGs around town.

CarsonF · August 28, 2021

2 hours ago, JimCost2014 said:

Welcome to the site.

So, to be clear, your mileage has decreased since the lift was installed, where you started at (15 MPG), now down to (13 MPG)?

How many mile on the truck? Changed gas station, different route to work, just all the standard questions...

I’ve always used shell 87. 55,000 on the truck. Yes it’s been decreasing since the lift was installed. My buddy has a 2015 with the same set up and he easily gets 17-18 mpg. Just wondering why mine was so much lower.

JimCost2014 · August 28, 2021

9 minutes ago, CarsonF said:

I’ve always used shell 87. 55,000 on the truck. Yes it’s been decreasing since the lift was installed. My buddy has a 2015 with the same set up and he easily gets 17-18 mpg. Just wondering why mine was so much lower.

Just some guesses, changing the air filter on a reular basis?

Maybe check your plugs and see how they look? A good fuel additive run through a couple of tanks.

Is the truck running any different since the decrease started happening? I don't think they have switched over to the winter blend gas yet which always kills MPG.

MikeBMW · August 28, 2021

38 minutes ago, JimCost2014 said:

I *might* have a bit of a lead foot (don't want to lose my drive safe and save State Farm insurance discount) but all of my driving (95%, anyway) is city driving - stop signs, waiting at stop lights often, etc).
I don't really care since my office is only two miles from my house.
I haven't really tracked the few highway miles I've driven but I do design work at some farms in the area that require a bit of highway miles as well as getting out of town and, combined, I can, sometimes, get to 15-17 MPG.
I've yet to try a full highway MPG test, though.

Edited August 28, 2021 by MikeBMW

JimCost2014 · August 28, 2021

8 minutes ago, MikeBMW said:

I *might* have a bit of a lead foot (don't want to lose my drive safe and save State Farm insurance discount) but all of my driving (95%, anyway) is city driving - stop signs, waiting at stop lights often, etc).
I don't really care since my office is only two miles from my house.
I haven't really tracked the few highway miles I've driven but I do design work at some farms in the area that require a bit of highway miles as well as getting out of town and, combined, I can, sometimes, get to 15-17 MPG.
I've yet to try a full highway MPG test, though.

I feel your pain, my new job is 3.8 miles from home, so not doing the freeway driving any more catches up fast to the MPG.

Since our new "President" has taken office, gas is over 4 dollars a gallon again in the Seattle area, so the short commute/bad MPG does hurt quite as bad at the pump each week.

MikeBMW · August 28, 2021

13 minutes ago, JimCost2014 said:

Since our new "President" has taken office

Can we leave this stuff out of conversations, please?

Last I looked, this isn't a political forum?

Edited August 28, 2021 by MikeBMW

JimCost2014 · August 28, 2021

13 minutes ago, MikeBMW said:

Can we leave this stuff out of conversations, please?

Last I looked, this isn't a political forum?

Sure, I will blame my Governor next time, that way it is closer to home for me, and far from others.

MikeBMW · August 28, 2021

Just now, JimCost2014 said:

Sure, I will blame my Governor next time, that way it is closer to home for me, and far from others.

Well, you do you, but leave politics out of this forum, please.
I come here to get away from all that.
I want to know about our trucks and issues, mods, trouble shooting and all that.
Hey, that's just me, I guess.

JimCost2014 · August 28, 2021

1 minute ago, MikeBMW said:

Well, you do you, but leave politics out of this forum, please.
I come here to get away from all that.
I want to know about our trucks and issues, mods, trouble shooting and all that.
Hey, that's just me, I guess.

Will do.

Since we have run this post off of the road, check out your next mod, page 4 of this one:

Lambo’s 2021 GMC Sierra 1500 AT4 Build