6.7L mileage with oversize tires??

CHKelley · 04-23-2008, 10:56 AM

2007-2008 6.7L 4X4 owners: I'm getting 17+ mpg around town, almost 20 on the highway. I've been told this will increase somewhat as the cummins breaks in, maybe up to 22 on the highway.

I'm going to mount either 295, 305, or 315's on my 2008, wondering how everyone's mileage is with any of these oversize tires.

__________________
2008 QCSB 6.7L 4X4 2500 6-speed Mineral Gray

CW6.7 · 04-23-2008, 11:39 AM

Is that hand calculated?????? Most people bone stock are seeing 12-13. With MP-8 or some form of chip some are seeing 15, 16, 17. Again with the DPF delete gaining even more mpg's. Tires size will kill that in a hurry!!!

I have run about 3000k miles on my DPF delete kit and MP-8. I have been averaging 18 mpg. With 305/45-22's (about 33x12.5)

__________________
07.5 - QC - SB - 6.7L - 68RFE - Afe intake - TS MP8 - 5in Magnaflow TBE - Gear Alloy 22x9.5's with 305/45's - Bilstien 5100s - Ultralite 2 gauges.

6.7L OneTon · 04-23-2008, 11:43 AM

Those can't be hand calc'ed numbers unless you somehow drive downhill wherever you go. :-) I lost about 1-1.5 mpg off my hand calc'ed numbers when I went from the stock tires to 315/70 17s. The loss is about the same with the true 35" Toyos I'm running now.

__________________
2007.5 3500 SRW 6.7L, 68RFE, PW flares, UConnect, Infinity, EZ Gate,
KORE 2.5 Stemtop Chase system with control arms, 35" Toyo M/Ts

Garry Verheyden · 04-23-2008, 11:49 AM

I'd do anything to have that kind of mileage!! My 08 Mega Long has never seen over 13MPG. Mostly it would get 11 MPG. empty!! I took my 19.5's off and now am in the upper 12's. My steel 19.5's were 33-1/2" tall with the 245 tires. They ate 1-1/2 mpg average.

DUKFVR · 04-23-2008, 11:51 AM

Not a 6.7 ,but a 5.9 & I lost about 1 1/2-2 mpg when I went to 35's Toyo's.

__________________
2007 2500 5.9 CTD MegaCab 4X4 Patriot Blue, Carli Starter System, Thuren TrackBar, Carli L/T AirBags, 35/12.50/17 Toyo M/T's on Black H2 Wheels, Denver Offroad Front Bumper, Buckstop Rear Bumper, Wet Okole Seat Covers, WeatherTech Floor Mats, WeatherGuard Tool Box

DunesRunner08 · 04-23-2008, 11:55 AM

You don't even want to know how sheety my fuel economy is with the 40's on it...lol

CHKelley · 04-23-2008, 12:09 PM

The numbers I'm reporting (17/20) are the ones calculated by the overhead console electronics in my 2008. My truck is bone stock running 265/70/17's and I don't have a lead foot. Yet.

Maybe I should start hand calculating my mileage??

Anyhow, thanks for the replies so far. I'm sure I should expect 1-2 mpg loss if I increase a tire size or so.

__________________
2008 QCSB 6.7L 4X4 2500 6-speed Mineral Gray

kmwharley · 04-23-2008, 12:24 PM

Just curious to the guys that lost mpg with larger tires, did you correct for tire size? On my wifes truck she never remembers and when I tell her that because of the larger tire size she if off 10% I see a light :-). If you are not correcting for the tire size on the speedo then maybe you are not actually losing any, maybe a little? Just a question

DUKFVR · 04-23-2008, 02:15 PM

Quote:

Originally Posted by kmwharley

Just curious to the guys that lost mpg with larger tires, did you correct for tire size? On my wifes truck she never remembers and when I tell her that because of the larger tire size she if off 10% I see a light :-). If you are not correcting for the tire size on the speedo then maybe you are not actually losing any, maybe a little? Just a question

I hand calculte mine with the different size tire figured in. I lost about 2 mpg with the toyo M/T's. Running 315 BFG A/T's for summer & I lose about 1-1 1/2 mpg.

__________________
2007 2500 5.9 CTD MegaCab 4X4 Patriot Blue, Carli Starter System, Thuren TrackBar, Carli L/T AirBags, 35/12.50/17 Toyo M/T's on Black H2 Wheels, Denver Offroad Front Bumper, Buckstop Rear Bumper, Wet Okole Seat Covers, WeatherTech Floor Mats, WeatherGuard Tool Box

ricefarmer05 · 04-23-2008, 02:39 PM

Hand calculated i get about 19 on the highway and 14 around town

biggyb1 · 04-23-2008, 03:26 PM

my truck got 22 mpg on the way home from the dealership(trip 150 miles) gone down eversince. I was told that same crap, it will get even better once it breaks in. The over head now stays around 13 in city and up to 17 hwy. Mine is also a straight drive which is suppose to be better. I wouln't look forward to any better milage. 6.7 nice power but milage SUCKS and fuel here $4.19 a gallon.

__________________
Dodge man forever. Why stroke it when you could be Cummin? 2007.5 Dodge 2500 6.7, 6 on the floor.

CHKelley · 04-23-2008, 06:52 PM

Thanks biggyb1. I'm wondering if you've calculated your mileage or just read it off the overhead. I'll probably start calculating mine with every fillup and comparing it to what the truck tells me, if I don't pass out from the price at the pump. It's $4.24/gallon here...

__________________
2008 QCSB 6.7L 4X4 2500 6-speed Mineral Gray

04-23-2008, 10:56 AM	#1 (permalink)
CHKelley Cummins Fan Join Date: Mar 2008 Posts: 43 CHKelley's Truck Pics	6.7L mileage with oversize tires?? 2007-2008 6.7L 4X4 owners: I'm getting 17+ mpg around town, almost 20 on the highway. I've been told this will increase somewhat as the cummins breaks in, maybe up to 22 on the highway. I'm going to mount either 295, 305, or 315's on my 2008, wondering how everyone's mileage is with any of these oversize tires. __________________ 2008 QCSB 6.7L 4X4 2500 6-speed Mineral Gray

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04-23-2008, 11:39 AM	#2 (permalink)
CW6.7 Cummins Fan Join Date: Jul 2007 Location: Indiana Posts: 93 CW6.7's Truck Pics	Is that hand calculated?????? Most people bone stock are seeing 12-13. With MP-8 or some form of chip some are seeing 15, 16, 17. Again with the DPF delete gaining even more mpg's. Tires size will kill that in a hurry!!! I have run about 3000k miles on my DPF delete kit and MP-8. I have been averaging 18 mpg. With 305/45-22's (about 33x12.5) __________________ 07.5 - QC - SB - 6.7L - 68RFE - Afe intake - TS MP8 - 5in Magnaflow TBE - Gear Alloy 22x9.5's with 305/45's - Bilstien 5100s - Ultralite 2 gauges.

04-23-2008, 11:43 AM	#3 (permalink)
6.7L OneTon Cummins Fan Join Date: Oct 2007 Posts: 78 6.7L OneTon's Truck Pics	Those can't be hand calc'ed numbers unless you somehow drive downhill wherever you go. :-) I lost about 1-1.5 mpg off my hand calc'ed numbers when I went from the stock tires to 315/70 17s. The loss is about the same with the true 35" Toyos I'm running now. __________________ 2007.5 3500 SRW 6.7L, 68RFE, PW flares, UConnect, Infinity, EZ Gate, KORE 2.5 Stemtop Chase system with control arms, 35" Toyo M/Ts

04-23-2008, 11:49 AM	#4 (permalink)
Garry Verheyden Cummins Enthusiast Join Date: Jan 2008 Location: Aldergrove,B.C. Posts: 212 Garry Verheyden's Truck Pics	I'd do anything to have that kind of mileage!! My 08 Mega Long has never seen over 13MPG. Mostly it would get 11 MPG. empty!! I took my 19.5's off and now am in the upper 12's. My steel 19.5's were 33-1/2" tall with the 245 tires. They ate 1-1/2 mpg average.

04-23-2008, 11:51 AM	#5 (permalink)
DUKFVR Cummins Fan Join Date: Feb 2008 Posts: 48 DUKFVR's Truck Pics	Not a 6.7 ,but a 5.9 & I lost about 1 1/2-2 mpg when I went to 35's Toyo's. __________________ 2007 2500 5.9 CTD MegaCab 4X4 Patriot Blue, Carli Starter System, Thuren TrackBar, Carli L/T AirBags, 35/12.50/17 Toyo M/T's on Black H2 Wheels, Denver Offroad Front Bumper, Buckstop Rear Bumper, Wet Okole Seat Covers, WeatherTech Floor Mats, WeatherGuard Tool Box

04-23-2008, 11:55 AM	#6 (permalink)
DunesRunner08 Banned Join Date: Mar 2008 Location: Phoenix Posts: 289 DunesRunner08's Truck Pics	You don't even want to know how sheety my fuel economy is with the 40's on it...lol

04-23-2008, 12:09 PM	#7 (permalink)
CHKelley Cummins Fan Join Date: Mar 2008 Posts: 43 CHKelley's Truck Pics	The numbers I'm reporting (17/20) are the ones calculated by the overhead console electronics in my 2008. My truck is bone stock running 265/70/17's and I don't have a lead foot. Yet. Maybe I should start hand calculating my mileage?? Anyhow, thanks for the replies so far. I'm sure I should expect 1-2 mpg loss if I increase a tire size or so. __________________ 2008 QCSB 6.7L 4X4 2500 6-speed Mineral Gray

04-23-2008, 12:24 PM	#8 (permalink)
kmwharley Cummins Fan Join Date: Mar 2008 Posts: 33 kmwharley's Truck Pics	Just curious to the guys that lost mpg with larger tires, did you correct for tire size? On my wifes truck she never remembers and when I tell her that because of the larger tire size she if off 10% I see a light :-). If you are not correcting for the tire size on the speedo then maybe you are not actually losing any, maybe a little? Just a question

04-23-2008, 02:39 PM	#10 (permalink)
ricefarmer05 Newbie Join Date: Mar 2008 Location: Dallas Posts: 4 ricefarmer05's Truck Pics	Hand calculated i get about 19 on the highway and 14 around town

04-23-2008, 03:26 PM	#11 (permalink)
biggyb1 Newbie Join Date: Nov 2007 Location: Winterville,NC Posts: 10 biggyb1's Truck Pics	my truck got 22 mpg on the way home from the dealership(trip 150 miles) gone down eversince. I was told that same crap, it will get even better once it breaks in. The over head now stays around 13 in city and up to 17 hwy. Mine is also a straight drive which is suppose to be better. I wouln't look forward to any better milage. 6.7 nice power but milage SUCKS and fuel here $4.19 a gallon. __________________ Dodge man forever. Why stroke it when you could be Cummin? 2007.5 Dodge 2500 6.7, 6 on the floor.

04-23-2008, 06:52 PM	#12 (permalink)
CHKelley Cummins Fan Join Date: Mar 2008 Posts: 43 CHKelley's Truck Pics	Thanks biggyb1. I'm wondering if you've calculated your mileage or just read it off the overhead. I'll probably start calculating mine with every fillup and comparing it to what the truck tells me, if I don't pass out from the price at the pump. It's $4.24/gallon here... __________________ 2008 QCSB 6.7L 4X4 2500 6-speed Mineral Gray