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labudski
12-04-2014, 06:56 PM
Anyone go to this size tire? I just like the fact that theyre rated for more weight (120 vs 115/112) than the 225's. Seems like a good idea?

NelsonSprinter
12-04-2014, 10:07 PM
yes many, just all have to be the same size , not sure if the spare will fit in it's place though

http://sprinter-source.com/forum/showthread.php?t=13904&highlight=245%2F75

.

turbodave
12-04-2014, 10:55 PM
I've got 245/75/16 Kumhos that were take offs from a 2011. According to the gps the speedometer is spot on but the odometer is reading 7% low.
Hope that helps
Dave

RedFord77
12-04-2014, 11:56 PM
I had 245/75/16 test fitted 6 months ago (on my aluminum rims), and they cleared on the front. I am also about to switch to 245/75/16.

I can get tires + rims off an NC3V. I would probably get the Kumho tires moved to my aluminum T1N rims, because they look better.

L8RSK8R
12-05-2014, 02:17 AM
My 2006 came with Michelin 255/55/18's. I recently went back to Discount Tire to have one tire replaced. They told me the tires mounted, were of the wrong load rating.
I asked them "why'd you mount the wrong tires" They had no answer.
I'd run up 20K miles on the wrong tires, they replaced them free of charge.

They mounted Pirelli Scorpion 255/60/18 112H XL BSW. Clearance on fronts is 3/4" from fender. I had to remove the front mudflaps.

alexk243
03-19-2018, 05:38 PM
This size will fit on a 2004 Dodge Sprinter T1N without rubbing? Is there an advantage to going to the bigger tire?

Nautamaran
03-19-2018, 07:19 PM
This size will fit on a 2004 Dodge Sprinter T1N without rubbing? Is there an advantage to going to the bigger tire?

Yes, unless it's a 118" built with 15" rims (check your door plate).

Some mods to mud flaps and tabs in the wheel wells may be required for 140" and 156" models.

Bigger tire gives higher sidewall, which can be let down for off-road use in sand and other soft surfaces. This gives a larger contact patch and lower ground-load, which can often (but not always) help traction and reduce sinking in sand and mud.
Downside to a larger contact patch on highway is increased tendency to hydroplaning in rain or to float on slush rather than pushing down through to the road surface.

The larger size also helps correct the speedometer under-read, which in turn increases the actual top speed when driving at the factory speed limiter.

-dave

alexk243
03-19-2018, 07:24 PM
Yes, unless it's a 118" built with 15" rims (check your door plate).

Some mods to mud flaps and tabs in the wheel wells may be required for 140" and 156" models.

Bigger tire gives higher sidewall, which can be let down for off-road use in sand and other soft surfaces. This gives a larger contact patch and lower ground-load, which can often (but not always) help traction and reduce sinking in sand and mud.
Downside to a larger contact patch on highway is increased tendency to hydroplaning in rain or to float on slush rather than pushing down through to the road surface.

The larger size also helps correct the speedometer under-read, which in turn increases the actual top speed when driving at the factory speed limiter.

-daveHow does this effect engine RPM, gas mileage?

Any issue with towing a trailer?

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Nautamaran
03-19-2018, 09:36 PM
How does this effect engine RPM, gas mileage?

Any issue with towing a trailer?

Sent from my Nexus 5 using Tapatalk

I run the stock size so can only theorize, but the larger tires will spin slower, which mimics slightly higher final drive gearing. This will raise engine load and reduce cruising rpm, which should improve fuel economy to a point (hills and head winds will be harder to face, so youíll gear down earlier), but will hurt acceleration and the brakes will feel softer under foot (but ultimately brakes will still lock up so it shouldnít impact panic stops in dry conditions; rubber compound has a stronger influence on braking).

Youíll feel the weight of a trailer more when accelerating or climbing a hill, but tires donít effect tongue weight rating. I donít believe thereís a max tow weight change going from the 3.72 diff to a 4.11, so you shouldnít see a downgrade going from 3.72 to the effective 3.55:1 on the taller rubber?

-dave

alexk243
03-23-2018, 04:06 PM
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. https://uploads.tapatalk-cdn.com/20180323/3788699ed1349102c8ed765142c4de0e.jpghttps://uploads.tapatalk-cdn.com/20180323/f3aa533cf3ba9382281f20e07c1e9c5b.jpg

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alexk243
03-24-2018, 04:56 AM
My van lists tire pressure at 55 front 79 rear with stock tires (225/75/16).

What pressure should I be using with bigger KO2's (245/75/16)?

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freestyle72
03-24-2018, 03:15 PM
My van lists tire pressure at 55 front 79 rear with stock tires (225/75/16).

What pressure should I be using with bigger KO2's (245/75/16)?

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You have to use the manufactures recommended tire pressures. Use the pressure rating listed on the sidewall of your tire.

alexk243
03-24-2018, 03:57 PM
You have to use the manufactures recommended tire pressures. Use the pressure rating listed on the sidewall of your tire.Manufacture of vehicle or tire? Both are different numbers... Isn't the sidewall rating a range?

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alexk243
03-27-2018, 04:27 AM
I thought I read someones thread about them using less tire pressure in a larger tire... but I cant seem to find it now.

Nautamaran
03-27-2018, 12:54 PM
Tire rating is just the maximum pressure the tire structure can safely hold, and should always be at or above the vehicle's door plate recommended pressure.

For a given axle weight, the tire's contact patch will have the same surface area at a given pressure regardless of tire diameter and width, so for same width tires as stock just use the pressures on your door plate. This will give you a slightly shorter contact patch, less tread deflection, and longer tread wear. You can use a proportionately lower pressure if you've gone to a wider tire, giving you the same length of contact patch (so still slightly less tread deflection due to increased diameter) while the extra width gives you more surface area and lower ground loading pressure, which is better over fluid materials like pea gravel or dry sand.

You *may* use less pressure with a larger diameter, since it's the length of the contact patch that determines the amount the tread will deflect when going from round to flat as it rotates through the contact patch, and this tread deflection decreases as the tire diameter increases. It's the tread deflection that determines the heat loading in the rubber, which feeds into the tire's weight and speed ratings, as exceeding the heat loading is what makes a too-low tire overheat and become a blow out risk.

Be aware that the extra width will also lead to earlier hydroplaning over puddles, regardless of pressure, and choose your speed accordingly.

-dave

alexk243
03-28-2018, 02:10 AM
Looks to be at 60 PSI all around. May add more to the rear on my trip.

Door panel says 55 front and 79 rear... Seems really high though.

Nautamaran
03-28-2018, 06:50 AM
My door panel says the same. The 79 psi rear pressure is for running rear at GAWR, which I’m nowhere near, so I run 55 front and adjust the rear according to my axle weight, generally around 70 psi.

-dave

alexk243
03-29-2018, 03:29 AM
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.

Midwestdrifter
03-29-2018, 07:23 AM
Wider tires will reduce fuel economy some. The softer compound used in the KO2 will also have a small reduction. I would guess 2-5%?

desertdog
03-31-2018, 12:18 AM
Possibly some of the decreased mileage is due to the larger tire effecting the odometer accuracy? Let us know what your next fill up mpg is. Thanks!

alexk243
03-31-2018, 02:48 PM
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:https://uploads.tapatalk-cdn.com/20180331/a95c5dc9aeba5a0f6698cb17ebafb536.jpg

alexk243
04-02-2018, 07:08 PM
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
04-03-2018, 08:41 PM
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
04-03-2018, 09:25 PM
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%.

vanski
04-03-2018, 11:42 PM
Poop.. Iíve 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:

alexk243
04-27-2019, 12:57 AM
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?

https://live.staticflickr.com/65535/47708798521_8134271f01_b.jpg

https://live.staticflickr.com/65535/46792689855_bb383671bc_b.jpg

Midwestdrifter
04-27-2019, 01:16 AM
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.

desertdog
04-27-2019, 01:22 AM
A 245 spare will fit in the rear undercarriage cradle if you drop the hinge mount to the two lower mounting holes. Takes 20 minutes max.

DRTDEVL
04-27-2019, 03:31 PM
Poop.. Iíve 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).

Gabe Athouse
04-29-2019, 06:34 AM
The only way to accurately calculate mileage and odometer accuracy is to use a gps track feature and compare to trip meter.

Garandman
04-29-2019, 12:25 PM
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).

p3424
07-23-2019, 02:52 PM
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
07-23-2019, 04:41 PM
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
07-23-2019, 04:42 PM
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.