245 75 16 ?

alexk243

KulAdventure
Will do. Was at 18 and 18.5 on highway run cross country. 70-75 MPH, minimal load/cargo.

Also, the vehicle speedometer was off before (showing 5 mph fast) and now it appears to be right on (compared to GPS). Will this effect the odometer? And if so would it be showing an accurate MPG now and the numbers I was getting before were false?

Now:
 
Last edited:

alexk243

KulAdventure
So I kept the van at 72 MPH after a fill up, highway at that speed the whole tank. 60psi front 70psi rear and I am getting 18.2 MPG... Very surprised that they tires had that negative of an effect on fuel mileage. Has anyone else experienced that? Even with the bigger tires.

(BFGoodrich KO2s)
 

desertdog

Member
I'm pretty sure that the 225/ 75R 16 stock size tires are giving us inflated numbers on our odometers. If we are showing 5 mph fast on our speedometers, it seems reasonable to assume we are actually covering less miles than shown on our odometers and consequently getting slightly less mpg then we figured. That would be the bad news. The good news would be that there are less miles on our t1n's then we thought...What does the forum think?
 

Midwestdrifter

Engineer In Residence
Odo is accurate with stock size. Speedo reads fast. Any time you increase tire width and/or ground clearance, fuel economy will suffer some. Softer tire compounds will do the same. A larger tire will make Apparent fuel economy drop due to odo under reading, 245/75r16 will reduce reported miles by about 7%.
 

alexk243

KulAdventure
about a year into the large tire size (245) and been great so far with no rubbing. However, I realized that my spare needs to be replaced. It is dry rotted and not holding air. What have you guys done with the spare?

If I run a smaller spare (225/75-16) will it put the van into limp mode if I have to use it? If I go with a bigger spare will it fit in the stock spare tire tray? Has anyone tried the bigger spare in there?



 

Midwestdrifter

Engineer In Residence
From what I understand, with some bending, 245/75R16 will fit the factory spare carrier. Someone will need to confirm.

If you run a 225/75R16 with the others 245 you will get one of two conditions. On the rear: possible trans LHM. 245 to 225 is close enough, that at lower speeds the TCM may not freak out. On the front: ESP/ABS will be disabled due to wheel speed mismatch. Again, if the tires are close, it may be okay at lower speeds.
 

DRTDEVL

Active member
Poop.. I’ve been multiplying my mileage by 1.04 based on this calculator and not 1.07... https://www.tacomaworld.com/tirecalc?tires=225-75r16-245-75r16

So I guess my actual average fuel economy is closer to 24 and not 23 :rad:
It depends upon the actual tire make, model, and size. For example, a Firestone Transforce HT in 225/75R16 LR-E has a diameter of 29.29 inches. If changing to a Cooper Discoverer AT/W in 245/75R16 LR-E, the new diameter is 30.35 inches, an increase of *only* 3.6%. If the new tire is a BFGoodrich Mud Terrain TA/KM2 in 245/75R16 LR-E, the new diameter would be 30.7 inches, a change of 4.8%.

Either way, the 4% number will be closer, but you need to know the actual dimensions before and after the change. I am currently exploring the first example given, as I am moving from the desert southwest to the upper Midwest, and my Firestones have about 75,000 miles on them already (will be about 80,000 by the time the move is completed). The Discoverer AT/W is a severe winter service rated all-terrain that is suitable year-round, whereas the Transforce HT is known for its long service life (hence 80,000 miles on the set with tread remaining), not its winter traction (treacherous, at best).
 

Garandman

Active member
When we put 16” alloys on our 118 we went to 235/65 x 16. The nominal rolling diameter is 28”. The nominal rolling diameter of the stock tire was apparently 27.7”.

Speed at an indicated 70 is 68mph for both. Don’t anticipate any problems using the stock spare (put 5 lug nuts in the glove box).
 
Last edited:

p3424

Active member
3 years with Defender LTX - LT245/75R16/E on 2006 T1N 140 WB, including the spare since its all the same steel rims. Probably the most trouble free tires I have had in all the cars.

I had to heat bend the front plastic bumper, but still slight rubs to tires on occasions during full steering turns. Since the rubbing is so slight and no marks on tire, I haven't bothered to bend the plastic further. Being a Dodge branded sprinter, I suspect the plastic bumper was probably a hack... If it weren't for the plastic bumper, tire of several size larger probably could fit easily.
 

ions82

Member
Hmm. And here I was thinking that I should go with 235/85/16 (narrower and taller for smoother ride and more efficiency.). I'll have to take a closer look to see if it may be feasible. My van will never go off-roading where traction might be an issue. Just a prisoner of the highway.
 

Midwestdrifter

Engineer In Residence
Taller tires won't improve fuel economy unless you have a an unusually high gear ratio. In fact lifting the vehicle at all will reduce fuel economy.
 

DustyDave

New member
Installed 245/75/16 KO2's on the van yesterday. Only rubbing is on the mudflaps, but that is easily fixable. I'll update more when I drive it cross country next week.


Sent from my Nexus 5 using Tapatalk
G'day mate, how did you fix the rubbing on your mudflaps?
Cheers Dave
 

TinManKC

“12 Reyo
Yeah I'm 60 front and 70 rear right now. I saw a big decrease in fuel mileage though... Went from 22 to 18 on this trip... Any thoughts? Can this new KO2 tire do that? Was hoping it would increase fuel mileage.
KO2’s will give you a milage hit.Great off road tire, passable on road.
 

Top Bottom