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it'll be noticeable...its not that your loosing any power but your in effect changing the final drive ratio with the larger diameter.

For example....29" standard tyres and 3.73:1 (auto) from factory.

With simple mathematics we can work out what the effective final drive ratio becomes with 33" tyres as follows -

3.73/33" X 29" = 3.28

So driving with a 33" diamter tyre will feel like driving on 29" tyres with a 3.28:1 final drive ratio instead of the 3.73 final drive ratio. That atleast some sort of a guide....am happy to be corrected if my maths is wrong.

I think thats the best way to compare it other than actually jumping in a vehicle and driving one. But then again how do you account for increase resistance due to tyre width increase and the friction with the road surface? Im not that mathematically gifted unfortunately.

When u guys talk about load rating is it for the tyre or the rim?
And what is the load rating and what does it mean?

dano85 wrote:When u guys talk about load rating is it for the tyre or the rim?
And what is the load rating and what does it mean?

Both Tyres and rims have load ratings, but in this instance there talking about load ratings on Tyres. Load ratings are the maximum safe weight a tyre can handle before it becomes dangerous. The manufacture puts the rating on the tyre placard for each vehicle, eg a light truck needs a higher load rating than a Suzuki swift ect...

So is it that a 15 inch steel rim can't handle the load rating or the tyres made for a 15 inch. Thanks

It depends on the size of tyre, the rim you will have to check if it's got the correct load rating. I'm running 32x11.5r15 on 15x8 rims and they are the correct load ratings on both.

Are 1000kg load range c ok?
Tyres are 33-12.5 15s i know they are to big legally but is the load rating ok?

dano85 wrote:Are 1000kg load range c ok?
Tyres are 33-12.5 15s i know they are to big legally but is the load rating ok?

Exactly the tyre size I'd like to be running

I'm pretty sure the 33x12.5r15 arnt up to the load limit required for the lux. Im on tappatalk so I can't double check for you. I'm only going by memory. Have a search around as it has been brought up before in heaps of threads.

i just read this reguarding load rating viewtopic.php?f=27&t=8721&p=115255&hilit=load+rating#p115255
verry informative
thanks guys

Most 33/12.5 x15 load rating is 108 / 109 Q which is under the 110 / 112 required by our trucks.

The gearing isnt too bad day to day. It would be less noticeable in an auto than a manual as 1st bloody gear is geared too high to start with then the larger diameter makes it worse. Once your moving you dont notice it and at highway speeds the lower revs saves you fuel. I consistently get 9L per 100kms out of my D4D.
Off the line it is harder to get moving from the dead stop, it sort of dies for a second then once it moves and the turbo kicks in its off and with my steinbauer and humex exhaust i havnt had another diesel get near me, even my mates 4.2 patrol with almost 10k worth of turbo, exhaust, and engine mods cant catch me off the line or a rolling start. Pisses him off too lol

How ever load it up with camping gear or put he boat on the back and you really notice the difference. It takes alot more to get moving and add a incline to it and well.... good luck. Even pulling a 4.2m tinny up a boat ramp needs low range so you dont ride the clutch way to much to get it moving and the same goes for stoping and starting on inclines out bush with a load.

I really want to run nitro 4.1 diffs in mine to make it right again, but the stuffing arround with the prado diff housing and center puts me off, I could do 90% of it myself in the shed but i just cant see the point of that much stuffing arround. I have have to settle for the 3.9's that will fit. But i know as soon as i do someone will make the 4.1's for our size front diffs. So if you want to tow alot, re gearing is a must !!

The width is the main issue, i have a -12 offset which is very wide, my tyres are also 305's or 12.5inches and required the trimming of the body mount (see my build) but guys are running the same wheel as me with the -12 offset but with 265 wide tyres with very minimal or no trimming. I dont have any trouble with it wandering on the road as some may think i would with 305's.

However when the tread gets low they will aquaplane and as the tyre gets old and hard there is traction issues. Its the same concept as a dozer track. Say my truck weighs 2t with stock tyres it has say 40 square inches of rubber contacting the road in total so that 2t t is devided by 40 which is 50kg per sq inch pressure on the road. Now add 33's at 12.5 inches wide and now you may have 100sq inches of rubber contacting the road, divide the 2t by that and you only have 20kg of pressure on the road per sq inch. Thats less than half, thats why you dont sink in the sand and how heavy dozers, excavators and tanks dont sink.
But with that reduced pressure on the road it breaks traction much easier, throw in slippery conditions like rain and you get the picture.

But for off roaders like us the extra ground clearance makes it all worth while, and they look shit hot too !!!

Hope that helps

Drew wrote: It would be less noticeable in an auto than a manual as 1st bloody gear is geared too high to start with then the larger diameter makes it worse.

Other way around Drew.....

More noticeable in an auto because 1st gear in the auto's is ALOT taller than first gear in the manuals. Manuals will get off the line easier.

1st gear in the D4D M/T's R151F is 4.313
1st gear in the D4D A/T's A340F is 2.804



Thats a 35% difference.

Why they made the auto's geared sooo tall beats the heck out of me.

If only it was a 5 speed auto, I bet 1st wouldn't be geared so high

we can only wish/dream.....that would have been the right thing to do....have first as a crawler gear only usuable when in low range atleast if anything....

True maxx but you dont have to ride a clutch to get the truck moving lol
In an auto you just stab the throttle and go but in the manual you really notice it as you have to use the clutch to get it moving.

my only worry is will it damage my auto, turbo or drive train? cause the wear and tear must give in at sum stage..any way more height means more fun for me!!

my auto drives awesomely with the 33's on, still has plenty of torque etc etc...even offroad its still good..H4 is fine for most tracks that i go on, L4 is awesome tho, but if i HAVE to use it it means im on a track that im gonna get into trouble...absolutely love my auto, good for everything

PIGD4D wrote:my only worry is will it damage my auto, turbo or drive train? cause the wear and tear must give in at sum stage..any way more height means more fun for me!!

You'll only damage it if you abuse it. I've done 85,000 km so far since the first week I had her on 33's and the auto is fine.

Drew, that's the main reeason I got an auto as I knew I was getting 33s straight away and the problems associated with clutches.

Autos I believe although not perfect have their advantages offroad.

mmaaxx wrote:
Autos I believe although not perfect have their advantages offroad.

im gonna second that...getting up step ups and ledges, you see the manual boys hitting them and riding the clutch...me and other auto can just push up against shit and then throttle over it...auto is very forgiving

yeh true ive notice i can ease up over shit better than my mates in there manuals..i prob got a few more months left out of the all-terrains which have been fantastic.. i have 16 by 8 king rims not sure wot off set tho dose that matter when going to the 285's ??