MPG loss with rims and tires?

mx711yam · 10-11-2008, 12:31 PM

Hey guys I'm looking at getting either a 2wd or 4wd Cummins. Either way, I'm going to put 20's on it. But with the 4wd I will obviously have to put bigger tires (33's) and I know I will be losing some MPG there. So should I get a 2wd or 4wd and how many miles a gallon are you 4wd guys losing with the bigger tires and rims?

Last edited by mx711yam : 10-11-2008 at 12:37 PM.

FIRE-Z-426 · 10-11-2008, 01:12 PM

I gained mpg going from a 33 to a 35... went to a 35 to a 37, and well I think that will be a different story.....

__________________
'04 305/555 3.73's nv5600 6" lift w/20's in 37's. S.C. Flashpaq, boost elbow, Quad fooler, 5 A.M.phantoms, Valair k/c, tailgater switch, 2nd gen intake, stock pipe w/4" bullet & 5" tip, tossed the intake baffles and silencer ring..370hp/821ftlbs

highersmoke24v · 10-11-2008, 01:13 PM

Well with a 2wd 6spd I get 19 hauling/highway and 24 all interstate. It would prob be eaiser to put 20s on a 4wd though.

__________________
2002 Cummins HO 6spd edge comp, K&N, Airdog 150, DDP's I, Southbend OFE, 1 1/2 lift, clear roof lights, SP turbo timer, boost elbow. Boost, EGT, fuel pressure gauges, 4in exhaust, Twin Hadley Air Horns!

upnya · 10-11-2008, 01:26 PM

i have a 01 dodge2500 4x4.
when i bought it, it had 20" wheels with 305/55/20 .
all terrains on it.
was getting 16.5 mpg's.
just put some hummer 17's on with 315/70/17's
bf goodrich all terrains and lost 1 mpg.
the hummers are about 1 inch overall height taller.
but the 20's weigh about 15 lbs more each.
i thought the weight would make mpg worse .
guess i was wrong..
gonna pick up some stocks see if they get any better
So if you want sum hummers or 20's... both sets
are up for sale.. will take partial trade on some stocks.

BillyRam · 10-11-2008, 03:48 PM

As a rule the more rubber that contacts the road the more drag. Larger tires weigh more and take more torque to get rolling. Smaller tires inflated to 60 lbs will give you the most mpg. Large tires properly inflated have a large contact patch and give less mpg. Mud tires have even more friction, run hotter and use even more fuel. But small tires don't look good on our trucks and if you are running over 600 hp they are dangerus. I can get 19 mpg with 33s running 45 psi in the front and 35 psi in the rear. If you over inflate 35s you could probley get just about the same but with 3.73 gears they will kill your stop and go milage. 4.10s do better with 35s than 3.73s. 35s look better with a 4" lift too.
Billy

__________________
Garmon tranny SunCoast ProLoc
HTT ProStreet 66/71/13
652hp/1254tq=11.91/111.59-1/4

10-11-2008, 12:31 PM	#1 (permalink)
mx711yam Cummins Fan Join Date: Sep 2008 Posts: 40 Thanks: 0 Thanked 0 Times in 0 Posts mx711yam's Truck Pics	MPG loss with rims and tires? Hey guys I'm looking at getting either a 2wd or 4wd Cummins. Either way, I'm going to put 20's on it. But with the 4wd I will obviously have to put bigger tires (33's) and I know I will be losing some MPG there. So should I get a 2wd or 4wd and how many miles a gallon are you 4wd guys losing with the bigger tires and rims? Last edited by mx711yam : 10-11-2008 at 12:37 PM.

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10-11-2008, 01:12 PM	#2 (permalink)
FIRE-Z-426 Diesel Freak Join Date: Nov 2007 Location: FLOSS YOUR TEETH, Northern Utah Posts: 584 Thanks: 8 Thanked 1 Time in 1 Post FIRE-Z-426's Truck Pics	I gained mpg going from a 33 to a 35... went to a 35 to a 37, and well I think that will be a different story..... __________________ '04 305/555 3.73's nv5600 6" lift w/20's in 37's. S.C. Flashpaq, boost elbow, Quad fooler, 5 A.M.phantoms, Valair k/c, tailgater switch, 2nd gen intake, stock pipe w/4" bullet & 5" tip, tossed the intake baffles and silencer ring..370hp/821ftlbs

10-11-2008, 01:13 PM	#3 (permalink)
highersmoke24v Cummins Enthusiast Join Date: Sep 2007 Location: Alabama Posts: 281 Thanks: 0 Thanked 0 Times in 0 Posts highersmoke24v's Truck Pics	Well with a 2wd 6spd I get 19 hauling/highway and 24 all interstate. It would prob be eaiser to put 20s on a 4wd though. __________________ 2002 Cummins HO 6spd edge comp, K&N, Airdog 150, DDP's I, Southbend OFE, 1 1/2 lift, clear roof lights, SP turbo timer, boost elbow. Boost, EGT, fuel pressure gauges, 4in exhaust, Twin Hadley Air Horns!

10-11-2008, 01:26 PM	#4 (permalink)
upnya Newbie Join Date: Sep 2008 Location: sacramento Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts upnya's Truck Pics	i have a 01 dodge2500 4x4. when i bought it, it had 20" wheels with 305/55/20 . all terrains on it. was getting 16.5 mpg's. just put some hummer 17's on with 315/70/17's bf goodrich all terrains and lost 1 mpg. the hummers are about 1 inch overall height taller. but the 20's weigh about 15 lbs more each. i thought the weight would make mpg worse . guess i was wrong.. gonna pick up some stocks see if they get any better So if you want sum hummers or 20's... both sets are up for sale.. will take partial trade on some stocks.

10-11-2008, 03:48 PM	#5 (permalink)
BillyRam Cummins Fanatic Join Date: Aug 2008 Location: North Augusta,SC Posts: 143 Thanks: 0 Thanked 1 Time in 1 Post BillyRam's Truck Pics	As a rule the more rubber that contacts the road the more drag. Larger tires weigh more and take more torque to get rolling. Smaller tires inflated to 60 lbs will give you the most mpg. Large tires properly inflated have a large contact patch and give less mpg. Mud tires have even more friction, run hotter and use even more fuel. But small tires don't look good on our trucks and if you are running over 600 hp they are dangerus. I can get 19 mpg with 33s running 45 psi in the front and 35 psi in the rear. If you over inflate 35s you could probley get just about the same but with 3.73 gears they will kill your stop and go milage. 4.10s do better with 35s than 3.73s. 35s look better with a 4" lift too. Billy __________________ Garmon tranny SunCoast ProLoc HTT ProStreet 66/71/13 652hp/1254tq=11.91/111.59-1/4