33" 35" tyres - why?

[snicko]

OK why do people put 33's or 35's (tyres) on their rigs??

[TuffTD42]

Gives more clearance under the diff pumpkins & also adds clearance all round. They make it easier to climb over rocks/ledges etc. Say for example you drove upto a rock ledge with 31's on & it came half way up the tyre, drive upto that same ledge with 35's & it will be 2" further down on that tyre hence less tyre the vehicle has to push up & over that rock ledge. Hope this makes sense.

Cheers Jono.

[snicko]

How do you measure the 33" or 35" ?

I have Cooper Discoverer S/T 265/70R17's on my rig, so where do you measure the size from?

[katwoman]

I went 33's cos I've got a 2 1/2 inch lift and wanted to fill in the guards a bit. I also only went A/T's because Im a learner.. One day I may get Katrol dirty and road tyres arent gonna cut it. Even the 33's have lifted the body, I reckon another 1/2 inch.

[katwoman]

How do you measure the 33" or 35" ?

I have Cooper Discoverer S/T 265/70R17's on my rig, so where do you measure the size from?

Im sure theres a thread here somewhere................. Ive got 285/75/16's which aparently is the same as 33's
Someone else will probaly know more than me.. End of the day, I think sizes go on what you want them for, and has been suggested to me is runs 2 sets of rims.. A/T's and muddies.

[Warnie]

265mm tyre width
tyre sidewall is 70% of the width of the tyre (there is 2 here as top and bottom of the tyres)
17" is the rim height

therefore
265mm x 0.7 x 2 x (1" / 25.4mm) + 17"
= 31.6"

[snicko]

Im sure theres a thread here somewhere................. Ive got 285/75/16's which aparently is the same as 33's
Someone else will probaly know more than me.. End of the day, I think sizes go on what you want them for, and has been suggested to me is runs 2 sets of rims.. A/T's and muddies.

Thanks Kat. I would like to get a set of muddies but not sure what the right questions or extra work is..

[Warnie]

I got over 2 sets of tyres its a PITA changing them for the wheeling I do. I went from 33" AT's and 35" Simex ET's to 33" Kumho KL's, more for touring duties.

[snicko]

265mm tyre width
tyre sidewall is 70% of the width of the tyre (there is 2 here as top and bottom of the tyres)
17" is the rim height

therefore
265mm x 0.7 x 2 x (1" / 25.4mm) + 17"
= 31.6"

Wow a formula! Now I know why we had them in school!! Shame I was'nt paying attention!!!

So to get a 33" I would need to get................???

[Warnie]

Thanks Kat. I would like to get a set of muddies but not sure what the right questions or extra work is..

The question you need to ask yourself is do you need mud tyres for the type of driving you do, and also do you need bigger tyres for extra clearence under your diffs. If you answered no to either of these questions then getting bigger mud tyres is a stupid thing to do. Staying with the correct tyre size does not void your insurance and you have more power with smaller tyre sizes. BUT if you want to get out there and get amonst it, a good set of All Terrains (Goodyear Duratrax, Mickey T 4 rib ATZ) or an easy going Mud terrain (KL71, KM2, Goodyear MTR, etc) in a 33 " will do you the trick.

[Warnie]

I am still in school somewhat. 5th year engineering at Uni lol

in a 17" rim 285/70/17 (11.25" wide) or 305/65/17 (12.3" wide) are a 33"

in a 16" rim 285/75/16 or 305/70/16

in a 15" rim 33/10.5/15 33/11.5/15 or 33/12.5/15

[NissanGQ4.2]

Also remember snicko your speedo will get thrown out with larger tyres ( not that there accurate anyway! ) but something 2 be aware of

[snicko]

The question you need to ask yourself is do you need mud tyres for the type of driving you do, and also do you need bigger tyres for extra clearence under your diffs. If you answered no to either of these questions then getting bigger mud tyres is a stupid thing to do. Staying with the correct tyre size does not void your insurance and you have more power with smaller tyre sizes. BUT if you want to get out there and get amonst it, a good set of All Terrains (Goodyear Duratrax, Mickey T 4 rib ATZ) or an easy going Mud terrain (KL71, KM2, Goodyear MTR, etc) in a will do you the trick.

Setting the rig up to do the Canning, Cape York, Kimberly, The Simpson, The High Country and any other dirt track I can find so I think I have a problem as no set up is going to do it all.

I need to find a happy medium!

[TuffTD42]

33's ask for 285/75/17 & 35's ask for 305/75/17.

[Warnie]

I would go a set of 33" muds and maybe a 2" lift for a bit more srticulation when you need it. When I went from 31" tyres to 33" tyres my speedo actually became correct, well speedo is 1km faster than GPS.

[katwoman]

Small hijack ( sorry) Love the new avatar Snicko, showing your true colours now !!

[TuffTD42]

as mentioned your speedo will be out. I put a thread on here not long ago with different speedo pinions to match different tyre sizes to get your speedo with in spec.

[TuffTD42]

Here we go http://www.nissanpatrol.com.au/forums/showthread.php?3423-Diff-ratio-tyre-size-speedo-gear-%28pinion%29&highlight=speedo+pinion

[snicko]

I would go a set of 33" muds and maybe a 2" lift for a bit more srticulation when you need it. When I went from 31" tyres to 33" tyres my speedo actually became correct, well speedo is 1km faster than GPS.

I have had fitted Old Man Emu springs and shockers which lifted up a couple of inches so 33" muds should be OK?

[Clunk]

I have had fitted Old Man Emu springs and shockers which lifted up a couple of inches so 33" muds should be OK?

from what I've read and understand from others, they should do just fine

[damianovdd]

Here - a tire calculator:
http://www.tyresave.co.uk/tyresize.html



p.s. AB may be you should make a sticky post only with one (or more) tire calculator to help the forum members.

[snicko]

Here - a tire calculator:
http://www.tyresave.co.uk/tyresize.html



p.s. AB may be you should make a sticky post only with one (or more) tire calculator to help the forum members.

Thanks for the site... great help in determining sizes

[snicko]

Using the tyre calculator going from 265/70/17 to 285/75/17 is a difference in diameter percentage =6.97% actual = 56mm

These figures mean I need to change ??

[Clunk]

Using the tyre calculator going from 265/70/17 to 285/75/17 is a difference in diameter percentage =6.97% actual = 56mm

These figures mean I need to change ??

it would give you approx and extra inch in lift and take you from approx 31in diameter tyre to a 33in trye

[snicko]

it would give you approx and extra inch in lift and take you from approx 31in diameter tyre to a 33in trye

Do I need to change any suspension stuff??????

[Clunk]

Do I need to change any suspension stuff??????

havent you already had an Old man Emu lift?, if thats the case then no.

[snicko]

Good then thats what I will get. Thanks. Now go to see the bank manager!!!!!!!!!

[Clunk]

Good then thats what I will get. Thanks. Now go to see the bank manager!!!!!!!!!

can you get some for me while your at it ????? ahahahahahaha

[Mrowka]

Bigger tires turn big bumps into little bumps. You can demonstrate this yourself by playing with toy cars - a car with larger wheels can negotiate bigger obstacles than a toy car with smaller wheels.

So why don't we all have 54" tires? Big tires are not so good for handling and can increase the chances of a rollover. They also require more power to turn. This is not a knock on big tires, just understand that, like anything, there are advantages and disadvantages to fitting them.

Big tires also mean more wear on suspension components, bearings, etc. so make sure that yours are in order.

Further, if you get anything bigger than 33", you should also consider getting numerically higher differential gears to compensate. The bigger the tires, the more compensation is needed.

[growler2058]

Yeah snicko gotta say nice avatar update. Also in my opinion i would be fitting 33" mud tyres for the application you have described, mud tyres are also more capable on rocks and other harsh terrains not just mud. As a general rule mud tyres are "stronger" in the side walls, though there are some good All terrains which also have strengthened side walls. If you were to go 35's you would most likely need to be fitting reduction gears taller suspension etc etc.
Thats my 2 bobs worth

[Warnie]

For a GU with 2" lift you could fit 35" on a negative offset rim easily by only just removing your mud flaps before they get removed. As for gearing it depends on the intended purpose of the vehicle.

Snicko for you to fit 33"s all you would have to do is buy them and get them fitted. BUT check the distance between the radius arm and the tyre at full lock with your 31"s on and just add roughly an inch to see if they will rub. If you think they will rub then you might want to consider a negative offset rim to accommodate the larger tyres. My GQ with 33" tyres and the standard 0 offset rims and 2" lift scrubbed at full lock left on the radius arm on the LHS. Yours may do so also. Did you fit castor correction bushes/drop arms to fix up your diff alignment when you lifted also??? As this could eliminate the problem of rubbing on one side.

There are many things to think about. But I would just test the full lock thing and if you reckon they will fit then go for it.

[Bigrig]

Setting the rig up to do the Canning, Cape York, Kimberly, The Simpson, The High Country and any other dirt track I can find so I think I have a problem as no set up is going to do it all.

I need to find a happy medium!

I'd be going an aggressive all terrain and not a mud tyre - yes, you are hitting dirt and mud etc when you get there, but meanwhile at the batcave, you are traversing thousands of kilometres of bitumen - mud tyres also equal noise and additional fuel consumption ... Warnie mentioned a couple of brands below - I have the Mickey Thompson ATZ (all terrain) 4 rib pattern (the 4 is important as thy have a 5 rib pattern also). The 4 rib is somewhere between standard all terrains and mud tyres and they perform exceptionally well on the road, wet or dry (my wife has Cooper STT mud tyres on her Rubicon, and they are like ice skates on the road in the wet). The 4 rib is an aggressive enough pattern to tackle mud etc, but work well on gravel, sand and most importantly, bitumen!! Have a look in the "Clubs and Events" and "Trips and Treks" section for some videos of what we do on the QLD trips and you'll see a range of vehicles and tyres in action - if you intend on going more extreme than that, then go for mud tyres, if not, stick with 33" all terrains!! 35's will throw out your gearing and your speedo too much and you just don't need them (apart from also gaining the attention of the boys in blue!!).

[snicko]

I'd be going an aggressive all terrain and not a mud tyre - yes, you are hitting dirt and mud etc when you get there, but meanwhile at the batcave, you are traversing thousands of kilometres of bitumen - mud tyres also equal noise and additional fuel consumption ... Warnie mentioned a couple of brands below - I have the Mickey Thompson ATZ (all terrain) 4 rib pattern (the 4 is important as thy have a 5 rib pattern also). The 4 rib is somewhere between standard all terrains and mud tyres and they perform exceptionally well on the road, wet or dry (my wife has Cooper STT mud tyres on her Rubicon, and they are like ice skates on the road in the wet). The 4 rib is an aggressive enough pattern to tackle mud etc, but work well on gravel, sand and most importantly, bitumen!! Have a look in the "Clubs and Events" and "Trips and Treks" section for some videos of what we do on the QLD trips and you'll see a range of vehicles and tyres in action - if you intend on going more extreme than that, then go for mud tyres, if not, stick with 33" all terrains!! 35's will throw out your gearing and your speedo too much and you just don't need them (apart from also gaining the attention of the boys in blue!!).

Im happy with the Cooper S/T's so far but all I've done is bitumen, sand at home and sloppy mud on the Kings Canyon loop. I was not sure if they would be good enough for the big trips. I'll go and check out the threads you suggested and proberly come back here with more questions!!!!!! Thanks Bigrig

[snicko]

I have just looked at the videos made (well done) Lancruiser Mountain Park!!

OMG OMG OMG!!!! I want to do all that but in my shiny rig???

I have made a BIG MISTAKE!!!!!!!!! How can I take my shiny, did I say shiny rig there!!! Should not have bought a new one and its our only ride!!
Confusion has set in!!

[Bigrig]

I have just looked at the videos made (well done) Lancruiser Mountain Park!!

OMG OMG OMG!!!! I want to do all that but in my shiny rig???

I have made a BIG MISTAKE!!!!!!!!! How can I take my shiny, did I say shiny rig there!!! Should not have bought a new one and its our only ride!!
Confusion has set in!!

There's no need to flog them to the point of panel damage mate. We had one truck out there that was only 3 weeks old!! And he got through extreme tracks. Not everything you tackle is brute force and mods - driving technique and where/how you take lines is just as, if not more important!!

The only thing I would say, is you're intending on doing state forests etc, then be prepared for some "lantana linework" (scratches on the paint from bushes etc) ... sort of unavoidable, but mostly buffs out with a polish!!

[snicko]

There's no need to flog them to the point of panel damage mate. We had one truck out there that was only 3 weeks old!! And he got through extreme tracks. Not everything you tackle is brute force and mods - driving technique and where/how you take lines is just as, if not more important!!

The only thing I would say, is you're intending on doing state forests etc, then be prepared for some "lantana linework" (scratches on the paint from bushes etc) ... sort of unavoidable, but mostly buffs out with a polish!!

Thanks, that makes me feel better.
We have lots of scratches and a few deep ones from our local sand pit.
Patrols don't fit down many of the tracks so we try with the rig, to make them bigger!!
(I'm sure the Parks and Wildlife guys do that on purpose!!!)
Meguiar's scratch-x followed by cleaner wax is the best stuff I have ever used. Proberly why after 4 years the rig is still shiny!

[Bigrig]

Thanks, that makes me feel better.
We have lots of scratches and a few deep ones from our local sand pit.
Patrols don't fit down many of the tracks so we try with the rig, to make them bigger!!
(I'm sure the Parks and Wildlife guys do that on purpose!!!)
Meguiar's scratch-x followed by cleaner wax is the best stuff I have ever used. Proberly why after 4 years the rig is still shiny!

I pay a Duco guy about twice a year to do it for me. Fixes scratches (fills them properly), does paint touch ups, acid treats the rims to bring them back up to showroom finish, and a full cut and polish for $225 .. this includes repairing stone chips/rust spots also ... for that money to keep the rig looking semi-decent, it's worth it to me ...

[Warnie]

I look at it slightly differnent and think they are only panels and you don't need panels. But thats just me. Whatever you decide to go with / do just make sure you are comfortable with your decision and that you have fun enjoying what you chose to put on your car / where you choose to wheel it. Thats the main thing.

[Bigrig]

I look at it slightly differnent and think they are only panels and you don't need panels. But thats just me. Whatever you decide to go with / do just make sure you are comfortable with your decision and that you have fun enjoying what you chose to put on your car / where you choose to wheel it. Thats the main thing.

Hahaha!! Remind me never to lend you my car!! I value my panels!! LOL!!!

[snicko]

I look at it slightly differnent and think they are only panels and you don't need panels. But thats just me. Whatever you decide to go with / do just make sure you are comfortable with your decision and that you have fun enjoying what you chose to put on your car / where you choose to wheel it. Thats the main thing.

Warnie thats great advice.
We need to be happy with the skin (or panels!) we are in....!!!!
The tyre questions have been answered in my mind for what I want to do.
Every ones perspective on this forum is so valuable as each question has different layers with different answers for different people.
Thanks heaps guys!

[Ben-e-boy]

33" or 35" is imperial measurement and 265/70 is metric measurment but they still use imperial rim measurement

[katwoman]

Also remember snicko your speedo will get thrown out with larger tyres ( not that there accurate anyway! ) but something 2 be aware of

When I had 31 road tyres my speedo was 8 k's out. Now I've got 33 A/T's, the speedo is bang on.

[Bigrig]

When I had 31 road tyres my speedo was 8 k's out. Now I've got 33 A/T's, the speedo is bang on.

It was out before then and the new tyres have corrected it - the bigger you go, generally the greater the understate of speed (that is, your speedo is showing 100, but with 33's it'll actually be something like 104 you're doing, fit 35's and it'll actually be 108 or more that you're doing).

[AB]

I was 1km out of Bobs GPS on 31"s and with 33"s I'm out about 4km like you said above.

[Bigrig]

Don't forget, the laws changed a while ago overseas and not that long ago here [but we get overseas made vehicles], that all manufacturers had to drop the + or - a certain % rule on the speedo, and ALL vehicles MUST overstate your speed now - that is, speedo shows 100, but you're only doing 96 or something but always less than the stated speed on the guage ... putting 33's on any vehicle manufactured after when this occurred would simply make it run fairly correct ... back to the footy ...

[Warnie]

Any time snicko, glad we could be of assistance

[TuffTD42]

I have heard quite a few stories where some GQ's speedo 's were out with 31's then reading correct with 33's. It is possible that the previous owner had changed the speedo pinion to correct speedo with 33's or 35's?

[MudRunnerTD]

OK why do people put 33's or 35's (tyres) on their rigs??

Hi Snicko,

Given that this is your daily driver and you will spend allot of time on the bitumen between trips i would be thinking about sticking with your HWY Terrain tyres on the 17s in a 265 which will be good for 100,000ks and you will get good quiet comfortable commuting, good fuel economy, your speedo will be accurate (as good as it is from factory anyways). there are people stripping off the factory tyres all the time and you will likely get a good set with 90+% for a bargain on the net when you need your next set.



Setting the rig up to do the Canning, Cape York, Kimberly, The Simpson, The High Country and any other dirt track I can find so I think I have a problem as no set up is going to do it all.

I need to find a happy medium!


For the kind of touring you are thinking about i would be SERIOUSLY thinking about changing down to a 16inch rim and running 285/75-16s in an aggressive AT or Mud terrain tyre.

There is a few reasons why this is a good idea.

1. 16 inch tyres are cheaper!
2. in the outback if you shred a tyre a 16 will be much much easier to come by and be a fair bit cheaper to replace up behind burke somewhere ;)
3. If traveling with a camper trailer make sure you fit the same wheels and tyres to it for matched sets and more spare tyres.
4. If you are travelling with friends and theirs is an older vehicle it will likely have 16s ...More spares if necessary....You never know.
5. 16 inch rims are cheaper
6. If you bend a steel rim you can panel beat it if you need to in the desert.
7. Leaving your nice shiny Alloys at home will mean they will always be nice and shiny and not get all scratch up in the outback or up the Cape
8. did i mention that the tyres are cheaper and much easier to get?
9. Buy the 16s and dont waste them getting to work, they are your holiday tyre and as such will likely see you out for 5+ years of touring and the cost offset over that time frame will be negligible.

I run 16 in rims and 285/75-16 Khumo KL71s on my GU IV for touring and they are the bomb!

Hope that gives you something to think about.

Cheers MR

[snicko]

Thanks mate..yeah food for thought (This is'nt the weight thread!!)

Last year I bought a set of (5) Alloys on Trading post so the camper and 4bee have the same rims =10 Genuine Rims!! Got them for $350 each - 6 on the rig, 3 on the camper one spare. Took 18 months of looking!!!!!!!!! Payed off though.

Any particular type of steel rim - genuine or other brand your recomend so I can start looking again?

[growler2058]

Thanks mate..yeah food for thought (This is'nt the weight thread!!)

Last year I bought a set of (5) Alloys on Trading post so the camper and 4bee have the same rims =10 Genuine Rims!! Got them for $350 each - 6 on the rig, 3 on the camper one spare. Took 18 months of looking!!!!!!!!! Payed off though.

Any particular type of steel rim - genuine or other brand your recomend so I can start looking again?

The standard old sunraysia is a cheap, but good steelie i got brand new in 15" for i think was $77 each from a tyre joint cant go wrong for that coin!!

[big_fletch]

The standard old sunraysia is a cheap, but good steelie i got brand new in 15" for i think was $77 each from a tyre joint cant go wrong for that coin!!

Yep spot on mate, I paid $75 a rim from local place here..
Cheaper than a new set of alloys Hahaha

[Bigrig]

Yep - sunraysia's are tried and proven ...