Big Tires And Gas Mileage?

cmoitoza · March 24, 2010

Well I am about to buy a 03-06 silverado extended or crew cab 4X4 very soon. I have been doing much research on the trucks and have come here for all you experts to give me the final verdict! I am seriously considering aquiring a truck with an existing lift on it, or putting my own on shortly after I buy. My first concern is with gas mileage. If I run a six inch lift with 33" tires and do mostly highway driving, just how bad would the mileage be on average with a 5.3? I have a very light foot and drive with care. I also plan on running a cold air intake, true dual exaust, headers and possibly a power programmer to at least compensate for the tires. If anyone is wondering, i don't really need a lift and all the performance mods, but I still have to look good in the snow, or the dunes in pismo!! Also, would mileage or drivability differ by mounting a lower profile 33 on maybe a 20" versus mounting a taller 33 on a 16"? I know there are many questions here but any input is greatly appreciated! Thank you so much!

TRCM · March 24, 2010

Well I am about to buy a 03-06 silverado extended or crew cab 4X4 very soon. I have been doing much research on the trucks and have come here for all you experts to give me the final verdict! I am seriously considering aquiring a truck with an existing lift on it, or putting my own on shortly after I buy. My first concern is with gas mileage. If I run a six inch lift with 33" tires and do mostly highway driving, just how bad would the mileage be on average with a 5.3? I have a very light foot and drive with care. I also plan on running a cold air intake, true dual exaust, headers and possibly a power programmer to at least compensate for the tires. If anyone is wondering, i don't really need a lift and all the performance mods, but I still have to look good in the snow, or the dunes in pismo!! Also, would mileage or drivability differ by mounting a lower profile 33 on maybe a 20" versus mounting a taller 33 on a 16"? I know there are many questions here but any input is greatly appreciated! Thank you so much!

Don't know about the 5.3, but I had an old Dodge Ramcharger with a 4 bbl 360 in I built (~ 425 hp), 9" of lift, 4.56 gears, and 40" swampers.

Weighing in @ 6500 lbs, she'd turn 9.0 sec flat in the 1/8 mile @ the strip, and got 8 mpg on the road....maybe 9 if the wind was blowing right.

Now, with what you are considering, you got heavier tires, and a lot more wind resistance to overcome, so I'd say your mpg is gonna go down a good bit. Probably not as bad as my old truck did, but I'd venture to say it will go down 3-4 mpg from stock.

Gregorio · March 24, 2010

Lost almost 2 mpg highway going to 305/20 rubber on 2006 CCRB Duramax. My sister lost almost the same with her 22" wheels on her 2009 Denali SUV. Both we stock ride height. I expect you will lose more as you go higher up in the wind.

jblakeney · March 24, 2010

Well I am about to buy a 03-06 silverado extended or crew cab 4X4 very soon. I have been doing much research on the trucks and have come here for all you experts to give me the final verdict! I am seriously considering aquiring a truck with an existing lift on it, or putting my own on shortly after I buy. My first concern is with gas mileage. If I run a six inch lift with 33" tires and do mostly highway driving, just how bad would the mileage be on average with a 5.3? I have a very light foot and drive with care. I also plan on running a cold air intake, true dual exaust, headers and possibly a power programmer to at least compensate for the tires. If anyone is wondering, i don't really need a lift and all the performance mods, but I still have to look good in the snow, or the dunes in pismo!! Also, would mileage or drivability differ by mounting a lower profile 33 on maybe a 20" versus mounting a taller 33 on a 16"? I know there are many questions here but any input is greatly appreciated! Thank you so much!

When you increase total rotating mass over the OE figure without changing gears to compensating for the change in mass. You should loose fuel economy. With that said IT ALL DEPENDS on factors that are unknown.

What is the weight difference in the two wheels. It could weight out that the taller tire would balance out with the change of total mass.

The taller tire should increase. But the mass will decrease. Depends on the ratio.

TOOOO tall you will cause the engine to lug. To much mass and same thing.

With that all said. I had a 1996 F150hd 4x4 5.8l with 35's. I ended up going to 4.56 or 5.11's I don't remember which I stayed with (tooooo much water ran under the bridge since 98 when I did all that). I changed gears 3 times before I decided which one worked best. It got about 8mpgs........ But before I did anything to the truck it only got 12. Worst gear ratio had me down to 5mpg.... At the time gas was $0.99 or less (usd)... So 8mpgs was not that bad......... Heck my 01 2500 only gets 12 now and I HAVE NOT DONE ANYTHING WHATS SO EVER to it.

Also the 35's were about 130 lbs with rims, lugs, and wheel weights. OE's was about 90. SO 40 extra lbs.

Just my 2 cents....

Jbo

jro909 · March 24, 2010

bigger tires=less mpg

truck lift=lessens aerodynamics of the truck resulting in drag= less mpg

alot of factors, 5.3 is a great motor but i'd avoid the lift and get 285 tires, lifts look nice but they wear shit out faster and it sucks going to the pump every other day...

Spurshot · March 24, 2010

I go along with most of what's been said. Taller tires will draw more power to accelerate. Changing axle ratios will get some of it back, but not all. Heavier tires/wheels will draw more power to accelerate but not to the extent that taller tires will.

Lifting the truck 6" will significantly increase aerodynamic drag. Gas mileage at highway speeds will really suffer from this. Put that together with the tires you mentioned and I'd guess you could loose 20-30% fuel economy.

But heck, you only live once. Go for it if that's what you want.

clemsonblozz · March 24, 2010

I went from the stock 265 75 16 tires to a 285 mud tire and lost about 2.5 mpg right off the bat.. I have had lifted vehicles(a jeep, 1979 GMC),, and unless you are into rock climbing or are in the muck 60% of the time,, do your self a favor and don't lift anything.. You'lll be replacing ball joints, tie rod ends, cv joints, u-joints, ect.. You raise your center of gravity, which makes you more prone to roll overs,, and makes towing a joke..

MYZ-71 · March 24, 2010

my 01 has 3.73`s and a 3" body lift, running 35`s with mostly highway driving I still manage 16mpg but engine definitely lugs @60mph.

chakis24 · March 25, 2010

i tend to average a little over 16 on my trips back and forth to long island. 13-14 on my daily commute (mostly highway with some city thrown in). i could probably gain an mpg or so if i could just slow down- i usually cruise around 75.

i have 34 inch load range e terra grapplers on 17 x9 aluminum wheels with a 3 inch body lift. i also still have the stock 3.42 gears (unfortunately). its nice on the highway (im turning 1800 rpms between 75-80) but off the line sucks.

fcknmaw · March 25, 2010

I know its not a 5.3, but the 33's on my 2500HD didn't seem to hurt much. I just got 12.5mpg with 3 guys, 700-800lbs in the bed, and a head wind. Pretty good for a brick. Just go with 285's and save the money from the lift.

Z'06 · March 25, 2010

i tend to average a little over 16 on my trips back and forth to long island. 13-14 on my daily commute (mostly highway with some city thrown in). i could probably gain an mpg or so if i could just slow down- i usually cruise around 75.

i have 34 inch load range e terra grapplers on 17 x9 aluminum wheels with a 3 inch body lift. i also still have the stock 3.42 gears (unfortunately). its nice on the highway (im turning 1800 rpms between 75-80) but off the line sucks.

You'd pick up an MPG or so switching to 4.10 or 4.30 with those 34s and your 4L60E tranny, mainly due to better in-town mileage, plus you'd put less wear and tear on your transmission and engine.

chakis24 · March 27, 2010

You'd pick up an MPG or so switching to 4.10 or 4.30 with those 34s and your 4L60E tranny, mainly due to better in-town mileage, plus you'd put less wear and tear on your transmission and engine.

i know, but parts + installation = money i dont have. maybe with the tax check.

jro909 · March 28, 2010

i tend to average a little over 16 on my trips back and forth to long island. 13-14 on my daily commute (mostly highway with some city thrown in). i could probably gain an mpg or so if i could just slow down- i usually cruise around 75.

i have 34 inch load range e terra grapplers on 17 x9 aluminum wheels with a 3 inch body lift. i also still have the stock 3.42 gears (unfortunately). its nice on the highway (im turning 1800 rpms between 75-80) but off the line sucks.

You'd pick up an MPG or so switching to 4.10 or 4.30 with those 34s and your 4L60E tranny, mainly due to better in-town mileage, plus you'd put less wear and tear on your transmission and engine.

then his mileage with suck the big one on the highway..its a lose lose situation...lose the tires and get the mpg or vice versa...i accepted my 17 a gallon years ago lol

Z'06 · March 28, 2010

then his mileage with suck the big one on the highway..its a lose lose situation...lose the tires and get the mpg or vice versa...i accepted my 17 a gallon years ago lol

But on a 4L60E, the rule of thumb best all-around gear ratio is 4.10 for 33" and 4.56 for 35", so 4.10 or 4.30 would be fine for 34" tires. 4.30 may not even be an option for 4WD front axles, so the 4.10 would be great on the highway for 34s.

shadetree25 · September 10, 2010

Lifting hasn't made a lot of difference in mpg. 35's lowered it by 3 mpg. 05 Z71 5.3 got 16 hwy. bought Hypertech economizer programmer. Got 19. went to 35's gets 16. Deprogrammed gets 17. 1/8 mile time is a full second faster with stock program with the 35's. Also have a constant check engine light with economizer program. Hypertech technician says it is because of defective knock sensor. Deprogrammed it does not get a code but, programmed it always comes on. Will not use the economizer with the 35's.

Probably will use it with the 05 Yukon 5.3 stock tires. It just got 21.8 on a 600 mile trip through Texas hill country. May not be worth the trouble to program it.