255/75r17

[PradoJim Member Find all posts View Profile Close PradoJim]

Does anybody run these tyres and how do you go with clearance issues etc or how much lift did you need ? I'm thinking it might just scrape in with no issues, slightly taller than the 265/70 that a lot of people run but being slightly narrower may help. They give a very useful 19 mm ground clearance increase and suit a 4.1 alt diff ratio perfectly.

255/75R17 on a 150 series

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Not a very common size and so not really viable. Best to stick with 265/70R17. Bob Jane currently has a good sale on Nitto Trail Grappler G2 and Yokohama G012. Toyo AT2s are also at a bargain basement price.

[PradoJim Member Find all posts View Profile Close PradoJim]

No, they're not all that common, but are available here in Australia. There isn't a readily available diff alternate to deal with the 265/70 as neatly as there is for the 255/75. The word seems to be that the 265/70 do use more fuel and affect towing etc I'll probably be towing something in the 2.5 tonne area (3 door has 3 tonne capacity).

With a slightly narrower tyre and corrected diff ratio, my fuel use shouldn't be changed much and towing shouldn't be a problem.

However, I'm doing all my research before spending and over the life of the car, sticking with 265/70's will save me way more than I'll burn in fuel, I'm aware of that Not to mention the 255 price per tyre is pretty high.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

With a slightly narrower tyre and corrected diff ratio, my fuel use shouldn't be changed much and towing shouldn't be a problem.

Ahhhhh, no, that isn't correct. There is more to fuel consumption than matching tyre diameter and diff ratios.

From your other post I and everyone else with a 150 running 265/70 17 have the speedo now exactly correct with new tyres. Fuel consumption increase on two trips to the moon would still be less than the price of the 255/75 tyres AND new differential centres.

I have noticed less than 0.5L/100km increase.

Actually it is close!

At perigee the distance to the moon is 384,400km. Assume two round trips without circumnavigating either heavenly body so that is 1,537,600km. Assume 80,000km per set of tyres. (Rotating the tyres, fueling up, oxygen etc is your problem not to mention delivery of consumables). So 20 sets of tyres. I paid $335 each for my KO2s and a quick look showed some Goodyear thing in 255/75 for $450 each. So net extra cost of tyres is $9,200. Let's say you pick up used diff centres and all up get these fitted for $1,500. So you have spent $10,700.

At 0.5L/100km increase in fuel you spend an extra $10,378.80.

You are in front on your third trip though.

[Black 150 Member Find all posts View Profile Close Black 150]

Do Hema maps even cover the moon?

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

Do Hema maps even cover the moon?

Don't think so, that's why I didn't allow for any side trips.

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

It's quite obvious you wouldn't and couldn't drive to the moon ...................

You'd use a star gate like kurt russell did.

[MidLifeCrisis Out of control poster! Find all posts View Profile Close MidLifeCrisis]

Don't think so, that's why I didn't allow for any side trips.

You should allow for getting lost, its hard to see the destination during the day.

[PradoJim Member Find all posts View Profile Close PradoJim]

Love the moon analogies, saw Buzz Aldrin live at the State Theatre in Sydney not too long ago.

My principal reason for the 255/75..........19 mm extra ground clearance. I have a price on 255/75's Goodyear for $361 so that means I might be making headway on my second return from the moon

The other aspect of going 265/70 with stock ratios is the reduction in "oomph" for towing which is the reason why I'd consider changing the diff ratios and running an even taller tyre. The fuel consumption is less of an issue overall but I've seen some posts that show way over 0.5l/100 proportional increase when towing heavy loads (22 lt/100 towing 2.2 tonne I think from one respondent, I'll have to check though).

I found from my other fourbee the biggest effect on fuel consumption was going to wider taller tyres (still only 5% increase in diameter). On that car, it's around 15% more fuel burn. I bought a set of used stock rims and tyres to run around town and calculated a conservative return on my investment in a worst-case scenario of about 18 months albeit with the inconvenience of changing wheels when I'm going bush bashing (I do have formal training in statistics, don't invite me to any parties ).

But once again, I'm doing the research now. Met a bloke the other day out at Bathurst with stock sized tyres (265/65R17) in BFG, a bit of lift and snorkel. Car was dirty and looked used. He told me he's been up to Cape York on the Tele track with that fit out with no real problems so that might be the sensible way to go. Although he did ground out on ramp-over bending his step. Three door does have an advantage there.

Staying with stock sizes but getting good off road rubber is really the simple solution but I'm just concerned about ground clearance under the diffs/bash plates when the going gets a bit tough.

I do appreciate all the ideas, comments and feedback, that's why I joined.

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

My figures don't take into account towing. Just bare Prado. Fuel is a consumable. I don't tow that much anyway. Maybe a few thousand km per year.

Taller tyres present more Prado to the wind and the extra weight of the tyres would contribute more than a bee's dick of width increase.

[ttmx83 Member Find all posts View Profile Close ttmx83]

OK, so you decide to choose a different size tyre to everyone else and you are out in a remote area and stake 2 tyres. Now its's not going to be easy to find something that size. This was my main reason for upgrading my skinny GX rims to FJ Cruiser rims with 265/70/17.

The increase in fuel use is around 0.8L/100klm and that would be mostly from the weight of the tyres I chose, Cooper ST MAXX. They are much heavier than the originals,

Cheers Brad

[PradoJim Member Find all posts View Profile Close PradoJim]

Thanks Brad. That is an issue to consider. I have staked two tyres once.

At the moment there are two manufacturers that I can find in Australia supplying the 255/75 so they are available but extremely unlikely to be on the shelf anywhere outside of a big city.

There are US forums where they talk about using these tyres on Prados and they seem highly regarded. I haven't seen them on a 150 series though (as yet) and of course they're dime-a-dozen over there.

I don't know enough to comment on the weight effect on fuel economy. I'd imagine the increase in total weight of the tyres wouldn't be much more than carrying a small child but that may not be the same as when that weight is being driven (the weight difference in my other car is 4kg per tyre but your Coopers could be even more).

As for more Prado in the wind, that's not really true. Body/suspension lift puts more Prado in the wind, taller tyres don't change the frontal area of the car whatsoever. It does expose a tiny additional cross sectional area of the tyre to the wind, that would be about all and I'd imagine almost immeasurable in effect. But that's not really the purpose of this thread, just a discussion item which is all very welcome.

[raydes Advanced Member Find all posts View Profile Close raydes]

255/75/17 standard size on Jeep Wrangler, lots on Gumtree, they usually go bigger and sell them off.
I have them on my Prado, very little difference in size to a 265/70/17 ..

[PradoJim Member Find all posts View Profile Close PradoJim]

255/75/17 standard size on Jeep Wrangler, lots on Gumtree, they usually go bigger and sell them off.
I have them on my Prado, very little difference in size to a 265/70/17 ..

Fantastic. Any rubbing/clearance issues ? Do you need any lift for clearance ?

I'll check out Gumtree as well.