Largest Functional Tire Without Mods

[jamesl175]

Do you have a link to that Falken pressure chart, please? (For other sizes.)

Absolutely loving my Falkens also. Mine wears A/T4W in 255/80R17 on the stock steelies. I prefer narrow for wet road and wet snow performance, based on where I drive, and as a bonus the steering lightness/return also improved.

Yes - you just fill out the form here with your individual vehicle details and then they email across a document confirming the details. Quite a good service to be honest.

Tyre Approval Certificates / Tyre pressure recommendation

If car owners wish to make modifications to tyres/rims that diverge from the original vehicle combination, they must obtain official approval of the changes.

www.falkentyre.com

 

[Nimrod]

Hello ladies,

Anyone know what the largest tire size is that can be used without rubbing, binding, and without cutting the vehicle to make it fit?

I'm also wondering if there are any options out there for upper control arm replacement to properly lift the truck say... 4 inches, while retaining correct angles.

Lastly... I see that spare tire upgrade size will likely be limited by the left rear access door needing room to open before the right side... looks like about 2 inches further would be the max...?

I had 35" tyres fitted on mine with a 30mm lift... work really well and drives as well as the originals on steel sheels

 

[Paco Garcia]

255/85r17 Mickey T Baja AT. stock 17” steelies. Stock springs. 1000lbs of overland gear. No rub. Raises truck 2 1/8” @36F 40R psi compared to stock 265/70R17 BFGs.
View attachment 7875285View attachment 7875286View attachment 7875287View attachment 7875544View attachment 7875545View attachment 7875546

And still no rub aired down to 22F and 26R psi in the sand on the stops

Hello @Brandtnm , I don't know how you did the calculation, but according to my calculations the elevation you get in the vehicle due to the change of tires is around 3 cm, which does not match the 2 "1/8 (almost 6 cm) that you mention, there is a total difference in wheel height of just over 6 cm, which is 3 above the axle and three below

The calculation would be the following:
Series wheels: 265/70/17 where the total height of the wheel would be
17x2.54 + (265x70%) x 2 = 802.8 mm
Alternative wheel: 255/85/17 the total height would be
17x254 + (255x85%) x 2 = 865.3 mm

Total height difference between both wheels
865.3 - 802.8 = 62.5 mm
6.25 cm: 2 = 3.125 cm
increase in vehicle height at the same pressure 3.12 cm
Regards
Paco Garcia

 

[Brandtnm]

Hello @Brandtnm , I don't know how you did the calculation, but according to my calculations the elevation you get in the vehicle due to the change of tires is around 3 cm, which does not match the 2 "1/8 (almost 6 cm) that you mention, there is a total difference in wheel height of just over 6 cm, which is 3 above the axle and three below

The calculation would be the following:
Series wheels: 265/70/17 where the total height of the wheel would be
17x2.54 + (265x70%) x 2 = 802.8 mm
Alternative wheel: 255/85/17 the total height would be
17x254 + (255x85%) x 2 = 865.3 mm

Total height difference between both wheels
865.3 - 802.8 = 62.5 mm
6.25 cm: 2 = 3.125 cm
increase in vehicle height at the same pressure 3.12 cm
Regards
Paco Garcia

Hi Paco,

I didn’t have to calculate from published or theoretical numbers which are often inaccurate averages. I just measured the actual truck height on the BFGs at 36&40 psi. I measured my wading line (put in when the truck was new so I’d know wading depth regardless of tires, or load, etc,) when I dropped it off for the new tires. I then measured the same point when I picked it up. So these are the actual measurements from changing 6k mile stock BFGs to the MT at the same pressures. As always, others’ numbers may vary because of tolerance stacking.

 

[Commodore]

Hi Paco,

I didn’t have to calculate from published or theoretical numbers which are often inaccurate averages. I just measured the actual truck height on the BFGs at 36&40 psi. I measured my wading line (put in when the truck was new so I’d know wading depth regardless of tires, or load, etc,) when I dropped it off for the new tires. I then measured the same point when I picked it up. So these are the actual measurements from changing 6k mile stock BFGs to the MT at the same pressures. As always, others’ numbers may vary because of tolerance stacking.

I have the same MT 255/85r17 tires and I agree that it sure feels like the truck is more an 1 1/4 inches taller. I didn't bother taking an measurements but the 30% rear door wouldn't open without installing the spare on an offset bracket. It wouldn't open by a lot not a little.

 

[TCMColorado]

It is worth noting that it is not necessary to use an offset tire bracket to run the Mickey Thompson 255/85R17. I originally installed the bracket from Leitner but did not like how it looked so instead I removed the left and bottom studs holding the spare to the OEM carrier. The threading on these is reversed so turn clockwise to remove. I then added 3/8" of washers/spacers behind the left stud and 3/16" behind the lower stud. This then rotated the left side of the spare out away from the vehicle enough that it clears the ladder with a roughly 1/8" gap. The change is invisible if you didn't know it was there and the washers cost a couple bucks at the hardware store. Anyone want the Leitner bracket now taking up space in my garage.

 

[Commodore]

It is worth noting that it is not necessary to use an offset tire bracket to run the Mickey Thompson 255/85R17. I originally installed the bracket from Leitner but did not like how it looked so instead I removed the left and bottom studs holding the spare to the OEM carrier. The threading on these is reversed so turn clockwise to remove. I then added 3/8" of washers/spacers behind the left stud and 3/16" behind the lower stud. This then rotated the left side of the spare out away from the vehicle enough that it clears the ladder with a roughly 1/8" gap. The change is invisible if you didn't know it was there and the washers cost a couple bucks at the hardware store. Anyone want the Leitner bracket now taking up space in my garage.

That is a great solution. How is your view out of the backup camera? Not that it is great now but I recall it being basically useless before the Leitner bracket moved the spare up and over.

 

[TCMColorado]

Hello @Brandtnm , I don't know how you did the calculation, but according to my calculations the elevation you get in the vehicle due to the change of tires is around 3 cm, which does not match the 2 "1/8 (almost 6 cm) that you mention, there is a total difference in wheel height of just over 6 cm, which is 3 above the axle and three below

The calculation would be the following:
Series wheels: 265/70/17 where the total height of the wheel would be
17x2.54 + (265x70%) x 2 = 802.8 mm
Alternative wheel: 255/85/17 the total height would be
17x254 + (255x85%) x 2 = 865.3 mm

Total height difference between both wheels
865.3 - 802.8 = 62.5 mm
6.25 cm: 2 = 3.125 cm
increase in vehicle height at the same pressure 3.12 cm
Regards
Paco Garcia

The math is correct as stated but the actual measured diameter of the unweighted Mickey Thompson tire is 878.8 mm not the calculated 865.3 mm. This results in a height difference of 3.8 cm or 1.5 in. This is closer to the difference reported by Brandtnm but still does not explain the full height change. I suspect the measured diameter of the unweighted BFG tires is actually less than the calculated dimension of 802.8 mm. BFG tires are notorious for being well under the specified diameter.

 

[TCMColorado]

That is a great solution. How is your view out of the backup camera? Not that it is great now but I recall it being basically useless before the Leitner bracket moved the spare up and over.

The view from the backup camera is reduced but I still find it to be acceptable in use.