How bad does mileage get with bigger tires?

What size tires are you running and what is your mpg?

14 city and 17 highway with 37's on 20's with factory 3:73's and 6-speed allison.

Unloaded: 15.5 City and 18.5 Freeway @ 70mph with 35's on 20, 3.73's and 6 speed Allison
Loaded pulling 7K lbs...12.5mpg @ 62mph. :D

http://www.dieselplace.com/forum/attachment.php?attachmentid=54006&d=1200325679

With 40"s I get around 13-14mpg on the highway with my LMM.

Sam

~16.5 city / ~20 hwy
I also live @ 6200ft above sea level and decreases some when I get above 9,000ft.

Always run on Edge level 1 (Economy)
33" tires
3.73 stock gears
6 speed Allison tranny

14 city and 17 highway with 37's on 20's with factory 3:73's and 6-speed allison.

That's about what I get in my stock LMM right now.... 30" tires.

With 40"s I get around 13-14mpg on the highway with my LMM.

Sam

Do you have a Tune or Exhaust? (DPF delete?)

Do you have a Tune or Exhaust? (DPF delete?)

No to both. Stock from the Factory.


Sam

i get around 13-14 with mixed driving. I dont really ever have a tank that was just city or just highway. It kinda killed my mileage pretty bad.

15 City

20 highway only

I lost 2-3 mpg empty or towing boat 12-15mpg and 4-5 towing toyhauler loaded.8-10mpg. When I regear Im sure it will increase my mpg on bigger loads. A friend of mine straight piped his lifted LMM and did some computer mods and gained a steady 3mpg on his LBZ he barely noticed an increase in mpg. How long before you have to have it smogged?

I lost a couple MPGs going to 285s. Thinkin of liftin it and running 35s as I don't think I would lose much more mileage.

After about 6 tanks of hwy driving I'm avging 15.6 mpg with 6" lift and 35" Toyo MT's. That's with an edge evo on level 1 and driving mellow between 65-70mph. All calculations done by hand (tripometer/gals). The speedo is adjusted via evo and nats ass with gps.

With 315's (34+" tall) just a tick over 17.5 in the city. This with my PPE set on the 225 hp tune, and a 5 spped alli. Got the same mileage with 285's. Without the tuner, I was getting 15 in the city. I don't do much hwy / frwy driving. oh, and I have 3:73's in the differental.

With 315's (34+" tall) just a tick over 17.5 in the city. This with my PPE set on the 225 hp tune, and a 5 spped alli. Got the same mileage with 285's. Without the tuner, I was getting 15 in the city. I don't do much hwy / frwy driving. oh, and I have 3:73's in the differental.

Do you have any tranny mods or stock? Any slippage or limps running 225HP PPE?

Thanks...:beerchug:
Mike

I'm running my winter wheels/tires now (315/16's) my last tank I got 15.7 and this tank I got 16.3. It's been going up steady the last few fill ups. Just getting used to driving this truck.

This is hand calculated. My best with my 37/22 combo was 17.5 highway going 70.

Do you have any tranny mods or stock? Any slippage or limps running 225HP PPE?

Thanks...:beerchug:
Mike

Stock tranny for now, plan on gettin a SCIV soon..
No slippin or limps..I drive like a Old lady.......seriously..:D

23K on my truck. (LMM) and getting 20+ at 65 mph highway with 35's.
15 city driving.
I run PPE #1 tune on my truck.
Was getting just a touch more with 305's and leveling kit.
I thought I would loose a lot of mpg's with the lift but not so.
Although my mpgs have kept increasing as the truck gets more miles on it.
Seems like it is just starting to loosen up now....

Mine has zero mods as far as exhaust, tuner etc. and with my lift and tires I am getting 13.8 ( hand checked today )around town ( I don't drive it like grandma would LOL ). As soon as taxes come in, I am doing the exhaust and programmer.

23K on my truck. (LMM) and getting 20+ at 65 mph highway with 35's.
15 city driving.
I run PPE #1 tune on my truck.
Was getting just a touch more with 305's and leveling kit.
I thought I would loose a lot of mpg's with the lift but not so.
Although my mpgs have kept increasing as the truck gets more miles on it.
Seems like it is just starting to loosen up now....

Try bumping up to level 3, but drive Easy, I bet your mpg's go up, as it will even more with higher hp..at least that's my experience.

I wish I could see how those with 35's, lift, etc. are getting 17+ mpg, or how they have verified their speedo accuracy. This is my 2nd Dmax with lift. On my 2003 with 4" Rancho and 295's I could get 17.5 mpg if drove like Ms Daisy all the time and with the 2007 Classic I was lucky to get 17 mpg with 265's bone stock. I only lost about 1.5-2mpg with the lift and 35's and I was pretty happy with that. Knowing there are others getting 4+ more mpg then my truck is discerning. And I'm a stickler for accuracy which is why I spent 3 days dialing in the speedo accurancy via Edge Evo and GPS. It's probably accurante to within 0.001 mph :)

My data is Hand calculated & gps verified :exactly:

This is also my 2nd lifted DMax and I can tell you my 2002 dmax got no where near what this LMM gets.

i have 22" wheels with 35's and i do good to get 15.5 on the highway and 13.5 in town ... that is takin off sloooooooow:mad:

I'm running 37's with 3.73. hypertech on level 3 stacked with the edge on 3/5. Avg. 13.48-13.78 driving it hard in the city and about 14.8 if i drive like a sane person. Got as high as 19.87 on the highway but avg. is around 18. All numbers are hand calculated and mileage is gps verified.

I wish I could see how those with 35's, lift, etc. are getting 17+ mpg, or how they have verified their speedo accuracy. This is my 2nd Dmax with lift. On my 2003 with 4" Rancho and 295's I could get 17.5 mpg if drove like Ms Daisy all the time and with the 2007 Classic I was lucky to get 17 mpg with 265's bone stock. I only lost about 1.5-2mpg with the lift and 35's and I was pretty happy with that. Knowing there are others getting 4+ more mpg then my truck is discerning. And I'm a stickler for accuracy which is why I spent 3 days dialing in the speedo accurancy via Edge Evo and GPS. It's probably accurante to within 0.001 mph :)

From my research it seems that fuel milage on these trucks is, and has been, all over the board since day 1. Im not sure what it is...climate, driving style, engine break-in, or what, but my truck has always seemed to be on the upper end of fuel milage. Before the lift & efi live, I was seeing 16.5 city and 20.5 highway.

Now right after I lifted mine and before I did EFI Live, I was seeing 13.5 city and 15.5 highway. That was a 3 & 5 mpg difference just from the lift. Thanks to Trippin's Tow Tune, I got a lot of milage back.

As far as speedo goes on my particular truck, I adjusted it with EFI Live and checked it to a radar set up on the side of the highway and it was right on. I can't speak for anyone else though.

I wish I could see how those with 35's, lift, etc. are getting 17+ mpg, or how they have verified their speedo accuracy...And I'm a stickler for accuracy which is why I spent 3 days dialing in the speedo accurancy via Edge Evo and GPS. It's probably accurante to within 0.001 mph :)

I have verified mine numerous ways including but not limited to: Using trip meter over 10+ mile intervals on the highway and verifying with the mile marker posts, using a stopwatch with cruise set at 60MPH over 10+ miles to verify that it takes me 10 minutes to go 10 miles etc., PA has in some location "DM's"-Designated mile, watch 10ths on trip meter and verify with "DM", road side construction "Your speed is" signs(although they are not calculated like ordinary radar, and I also have a PA State Trooper buddy who radared(that spelled right?!!) me with cruise set @ 70MPH and I was dead on.

I mainly put highway miles on my truck and during the summer am between 17.5 and 19.2MPG, if I do have mixed driving in with a tankful or the weather turns to crap and gets frigid I will drop to 14.8-16.5ish. The winter REALLY takes a toll on mileage, between the "winter blend fuel" and the enormous amount of liquids in our trucks(2.5 gallons of COLD engine oil, trans. fluid, transfer case, rear end lube), all that thick fluid takes more fuel and effort to slosh around when its cold and thicker, as well as warm up times compared to warm/hot temps.

I run my Hypetech PPIII on level 3(95HP) ALL the time and typically run 5MPH over the speed limit on my way to work and usually right around the limit all other times, so usually between 55-70MPH. PA is notorious for its ROLLING hills which are in some cases NOT hills but small mountains, you folks in the Midwest and Southeast should be getting much better mileage than those of us that live in hilly, cold regions or out West where the speed limits are higher as well as the flow of traffic(75-90MPH) or bumper-to-bumper, no in between! I lived in San Diego for 5 years and it was either hauling a$$ or gridlock...

Cheers!:beerchug:
Mike

Getting 16.5 street and 19 highway. running 37's w/ 4:56 Gears. PPE tune 3. Usually i try and keep it under 2000 RPM on the street.... Unless i'm racing a Ricer!

I've never seen over 18.5mpg with two Dmax's now with both stock :( I've read most of the mpg threads on this forum since the forum was born and always scratching my head on how mpg's can vary so much across trucks. It's definately weird. Perhaps it's the color of the truck. So far for me, white and gray aren't winners in terms of mpg but the white 2003 got me around a little quicker :)

I've never seen over 18.5mpg with two Dmax's now with both stock :( I've read most of the mpg threads on this forum since the forum was born and always scratching my head on how mpg's can vary so much across trucks. It's definately weird. Perhaps it's the color of the truck. So far for me, white and gray aren't winners in terms of mpg but the white 2003 got me around a little quicker :)

Haha, white seems to work o.k. for me..:D

I didn't see any great, if that's what ya wanna call it..mileage until I did some mods, i.e. the airbox, catback, and the PPE tuner. Seems the tuner was the key, set on 120 hp level 3, I went from 15 mpg, to a tick over 16, when I bumped up to level 4 160 hp, I saw a 2 mpg increase, then I tried level 5 225 hp, and got a tick over a 2.5 mpg increase, all hand calced, and gps verified..what's surpriseing is, my dic isn't that far off..anyways, I'm geting 17.7 mpg, and have been for the last 3 1/2 months. Oh, that's 99% city driving. :D

Heyyyy Nick, you need to move it up to level 5, way better mpg's..

Tophog I'm with you. I can't get above 15mpg on my best day with a mix of city/highway, more highway. I've got duel exhaust, PPE (tried all levels). I easily lost 4-5 mpg's.:(

Tophog I'm with you. I can't get above 15mpg on my best day with a mix of city/highway, more highway. I've got duel exhaust, PPE (tried all levels). I easily lost 4-5 mpg's.:(

I know the lift plays a part in the mpg's, but just for giggles, what if anything have you done as far as mods to your exhaust and intake..?

A close friend and Duramax tech here on the board told me there wasn't a lot to gain on intake/exhaust mods on the LBZ's compared to the previous engines. Therefore I have left my truck stock since I'm not hot rodding this one. I did pickup about 1.5 mpg with the Evo as I was getting 14 mpg the first 3-4 tanks after the lift/wheels. Running the Evo on level 1 I'm getting right at 15.5 mpg every tank running 65-70 mpg and right @ 1600 rpm.

im running 285's @ 50 psi front and 55 psi. rear, i do alot in town. i calculate by hand at every fill up. my in town ranges from 14.2-15.8. the best i've recorded on the hwy was 19.8 with edge on 1/1. I am o.k. with that but these 20 mpg in town stories kinda make me wonder.
oh ya i am compensating for the 285's. = miles x 1.08 = true miles. is this correct?

A close friend and Duramax tech here on the board told me there wasn't a lot to gain on intake/exhaust mods on the LBZ's compared to the previous engines. Therefore I have left my truck stock since I'm not hot rodding this one. I did pickup about 1.5 mpg with the Evo as I was getting 14 mpg the first 3-4 tanks after the lift/wheels. Running the Evo on level 1 I'm getting right at 15.5 mpg every tank running 65-70 mpg and right @ 1600 rpm.


Well the LBZ's do have way more power than the LB7's...:D

Still with all the technology, you'd think they could up the mpg's too..

315/70R17 and I get about 14mpg highway at 70mph cruise control with mods below. I am testing mpg results with all Predator settings. So far no noticeable difference between 85 and 65. I am currently testing 40hp.
ac

im running 285's @ 50 psi front and 55 psi. rear, i do alot in town. i calculate by hand at every fill up. my in town ranges from 14.2-15.8. the best i've recorded on the hwy was 19.8 with edge on 1/1. I am o.k. with that but these 20 mpg in town stories kinda make me wonder.
oh ya i am compensating for the 285's. = miles x 1.08 = true miles. is this correct?

Just curious why you run the rears higher, do you haul all the time?
I'm empty the majority of the time and run the same PSI's as you only in the opposite ends (engine is WAY heavier than an empty bed, a$$ end bounces all over with high PSI's and empty bed).

i average 15-17 mix of highway and city driving.

Hammer, my mods are in my sig. No cat, banks duels, no air box mods, but other than air box I don't know of anything else to do. I pulled a 16ft enclosed trailer with two motorcycles in it 500mi each way and averaged just over 11mpg at 70-75mph.

Haha, white seems to work o.k. for me..:D

I didn't see any great, if that's what ya wanna call it..mileage until I did some mods, i.e. the airbox, catback, and the PPE tuner. Seems the tuner was the key, set on 120 hp level 3, I went from 15 mpg, to a tick over 16, when I bumped up to level 4 160 hp, I saw a 2 mpg increase, then I tried level 5 225 hp, and got a tick over a 2.5 mpg increase, all hand calced, and gps verified..what's surpriseing is, my dic isn't that far off..anyways, I'm geting 17.7 mpg, and have been for the last 3 1/2 months. Oh, that's 99% city driving. :D

Heyyyy Nick, you need to move it up to level 5, way better mpg's..


Gotta try it

I wish I could see how those with 35's, lift, etc. are getting 17+ mpg, or how they have verified their speedo accuracy. This is my 2nd Dmax with lift. On my 2003 with 4" Rancho and 295's I could get 17.5 mpg if drove like Ms Daisy all the time and with the 2007 Classic I was lucky to get 17 mpg with 265's bone stock. I only lost about 1.5-2mpg with the lift and 35's and I was pretty happy with that. Knowing there are others getting 4+ more mpg then my truck is discerning. And I'm a stickler for accuracy which is why I spent 3 days dialing in the speedo accurancy via Edge Evo and GPS. It's probably accurante to within 0.001 mph :)

I run an Avic Z1 so my speed was varified via GPS. I also have a Garmin Nuvi and a Garmin hand held, they all read about the same.

I stay at 2k or below as long as I'm not hauling. I believe 2k rpms and below is the key to good mileage.

With my 37's the mileage does suffer, I may go up in gears if I can't get 15mpg in the city with them this summer. The 315's are golden right now. I'm happy with 16+

Hammer, my mods are in my sig. No cat, banks duels, no air box mods, but other than air box I don't know of anything else to do. I pulled a 16ft enclosed trailer with two motorcycles in it 500mi each way and averaged just over 11mpg at 70-75mph.

Which PPE tuner do you have, and what level do you set it on when empty..?