Do Bigger Tyres Make That Much Difference

[StoneySR05]

G'Day All,

I currently have a set of 225/75/16 BFG AT’s and I would like to know if going from 225/75/16's (29.4") to 235/85/16 (31.7") would really make a big difference off road or not?

The reason why I ask is that I am contemplating either getting bigger tyres or some more accessories, like rear step bar, snorkel or something else.

I understand that the bigger tyre will lift the car higher and the diffs will be higher, but will I go just as far off road with the smaller tyres, maybe I am better off with more body protection.

I'm Confused!

[Hilux Max]

you'll get more ground clearance between the ground and diffs, the gearing will be out abit and takeoff will be slower and braking efficiency will be less. Upto you if you are prepared to sacrifice abit of the aforementioned items.

[kazdan69]

Hi ya Stoney,
From experience, the first thing you need is an upgraded suspension kit, that extra 40-50mm is a must, will also save you a bit of underbody damage. Then get the tyres, I'm currently running BFG 31x10R15's and am going to upgrade later to 32' Cooper STT, As far as all the bits an pieces go, you are really far better off to get them after you sort out your suspension.
The way I see it for my situation is-
Suspension
Tyres- ( they are nice alloys on the SR5)
Bullbar (winch compatible)
Spotlights-(Lightforce 240XGT)
12volt air compressor
Rear step/towbar
Snorkel
Dual Battery System
Winch
UHF
3 inch Mandrel bent stainless exhaust
Rechip of the CPU
Rock slider sidesteps
Brushbars
Long range fuel tank
Air lockers front and rear
ETC ETC. All these things take time as they take up lots of your hard earned cash- the big thing is to write a list out depending on your situation and what you wish accomplish on your weekends, whether it be off alone with the family, or away with friends. As each change of circumstance will mean a different set of priorities as far as the aftermarket buildup goes, and of course the budget. I would love to say this helps you, but I do know that this may confuse you even more, but take it one step at a time according to what you want to do, and don't be afraid to change the lists sequences. As my suspension is being customised to suit all my accessories and their weight, it doesn't go in for another 2-3 weeks,
after the winch and a few other bits and pieces.
Be Strong Grasshopper, remember Christmas comes but once a year, but there is also Birthdays, Fathers Day, and the secret stash the missus don't know about!!!!!!!

[StoneySR05]

Thanks Guys,

I have already done the OME suspension lift so I am looking for the next thing to target.

In the end I can have both tyres and rearbar but I would like to debate wether the bigger diameter tyres would make a significant difference off road or not.

I am expecting a phone call from a tyre shop today about a price for 235/85/16 Cooper STT today and I want to be able to say to them yes or no.

[Smithyworld]

Bigger tyres has to be one of the best mods for offroad driving as it is the only item that gives you more clearance between the diff and ground and the ground and the under carriage of the vehicle.

[StoneySR05]

I know what you are saying Smithy, this is doing my head in.

I look at the images on the website of the cars with bigger tyres and I say to myself " You Know You Want It".

To make matters worse do I buy a set of 16X7 rims with 265/75/16's or do I go the skinnies 235/85/16's. There would be about $500 difference between the two.

If I get another set of tyres that will leave me with 3 sets in total, standard tyres, 225/75/16 BFG's and the 32's.

MMMMMMMMMMMM - Help me make up my mind

[TOMUCH]

Mate, I don't know if its really all that necessary to get bigger thatn 31 inch tyres... I have done a lot of traveling on mine and although they have worn out pretty quick (due to speed and distances travelled on dirt roads and tracks) I cann not complain about the 31 10.5R 15s that I have... yeah 32s are nice to look at and will offer more height off road, but is it really worth the extra wear and stress you place on your cars components??? go the 31s they will take you anywhere you would really care to go in this country....Thats my two cents... Cheers TOMUCH

[StoneySR05]

A couple of weeks ago I went 4WD'ing with my neighbour in his Cruiser (lifted, 33's & double Difflocks) and one of his mates. His mate has a leaf sprung Hilux (31's & rear Detroit locker) and the Hilux went everywhere the Cruiser went and this was the hardest 4WD'ing that I had done, twice we had to winch up hill, getting up 4 foot high rock steps.

This is what made me start to think that you don't need the biggest tyre and after talking to the bloke with the Hilux he believes that the rear bar has been one of the best investments for his car.

32's still look the business!!!!!!!!!!

[Hilux Max]

Get the 32's Stoney (265's) you know you want them soooo baaad!!

How much tuffer wiould you hilux look with them on?

Yeah, I know, its not all about 'tuff-looking' but the 265's are a good size tyre and I dont beleive its overkill.

Anything bigger than that would be overkill......

Maybe I should've taken some of my own advice. Bugger!

[Danlux]

Go the 32's, you shouldn't notice to much difference on take of with the big V6 and an auto, you will notice a loss in braking performance and you have lower revs on the freeway, of course the added benefit of a little more ground clearance and of course they look better.

Just remember to get the right off set rim if you change rims.

[Hilux Max]

Dan, 16x7's with the standard +30 offset shouldnt be a problem with the 265's.

Its when you want them to stick out abit further that people start messing with offsets or if you want 33's or more.

Ive seen 265's or a few luxies at work and they've never had rubbing problems.

[Danlux]

Ah yes mmaaxx your right I was thinking more like 285/75/16 (33") on a 16x8 rim, sorry my bad

[felix]

Just a word on wheel offset, I measured mine today ( standard sr steel wheels) and it is 45p not the 30p that is constantly mentioned. If anyone else has actually got out there and measured it i would like to hear the results.

[Danlux]

The SR rim and the SR5 rim are different in size and offset so i believe

[Hilux Max]

SR wheel is 45 positive and the sr5 is 30 positive offset.

[Uteracer]

The day I picked up my new rig, I went to a tyre place, traded my new factory tyres on a set of Cooper ST 31's. It looks much better now. With those large wheel arches, the factory tyres looked a bit small...

[StoneySR05]

Stop There!!!!!!!!!!!!!

So, I have an SR and don't want to fit flares and want the tyres to sit under the guards. If I want to buy 16X7" rims do I need +45p or +30p offset.

I know it can be done as "Wade" & "Troyco" have done it.

I just found this table that shows wheel information, it says that all the rims for 6 stud 4WD model has a +30 offset and the 5 stud 2WD model has +45 offset.

Once again confused!!!!!!!!!!!!!

[felix]

That's an interesting chart stoneysr05, and yes now confusion does reign. The wheel I measured is the 16x6.0 J and it is 45mm! Measure your spare and see if you come up with the same result.

[StoneySR05]

Felix,

I just measured the spare and you are right, the 16X6 SR Steelie measures 135mm from the back of the rim to the mounting face and 45mm from the front of the rim and total width is 180mm.

This should give 45mm positive offset for the 6 inch wide rim.

I would imagine that the difference in offset between the 6" and 7" rim is to allow for the 1" difference in width. 1" divided by 2 is approx 15mm (12.7mm is the actual size).

So if you are buying a 7" wide rim you need to have a +30mm offset.

Does this sound right?


Carl

[felix]

stoney

I'm guessing that might be right but the next question is..........do the SR and SR5 models both have the same length wheel studs?

The alloy wheel is probably thicker than the steel so the studs might be longer. I say this because I'm sure someone on this forum mentioned that they put alloys on their SR and found insufficient length in the studs to be safe, only five rotations or something like that.