Swapping 15" for 16"

[Duzzy]

Hi there, first post here
I drive a MQ 2016/17 mitshubishi triton glx+ with alloys and 16 inch rims with 245/70R 111S RF tyres (6 wheel nuts). I also have a mars camper with 15 inch alloys (also 6 wheel nuts). I'm looking to put Sunraysia steel rims on all 8 wheels my question is can I safely change the 15" rims to 16" rims. Below is a pic of my camper with the 15"s. Any assistance is appreciated.

Regards Darren
http://4x4earth.com/forum/index.php?threads/can-i-exchange-my-mars-campers-15-s-for-16-s.41582/

[NowForThe5th]

Welcome to the forum.

It all depends on what wheels/tyres are on the camper now. It's a bit hard to tell from the thumbnail on your link, since that forum requires registration & sign in to view pictures.

Why don't you start by trying to fit one of your Triton wheels to the camper? At least then you'll know if wheel stud pattern/size is compatible and have some idea of how the standard Triton offset sits with respect to the trailer mudguards. From there you should be able to calculate whether the change in offset with the Sunnys has any chance of working.

It looks like your trailer tyres are P235/75R15 and clearance to the mudguards is fairly tight. My initial response is that it might not work with the standard Triton tyres, probably won't work if you intend on going up a size in tyres.

You are aware, aren't you, that changing to steel wheels can adversely affect ride and braking?

[BillMcQuade]

The Triton wheels probably won't fit, as trailers generally run around 0 offset. I converted my caravan from 14" Sunraysia rims to 16" Triton rims, and had to used spacers (machined from forged alloy, and not legal). I will be changing to 6 stud rims with the correct offset.

Also note, that changing rim size on the camper is illegal in NSW, unless the original plate that specifies the rim/tyre size mysteriously replaces itself with a new one......

There is also the issue of the braking on the camper being affected by the greater force induced by a larger wheel radius, plus the corresponding reduction in axle weight.

Steel rims on the Triton will reduce the braking force on the already marginal OEM brakes.

[NowForThe5th]

plus the corresponding reduction in axle weight.

Did you mean increase in unsprung weight, Bill?

[BillMcQuade]

plus the corresponding reduction in axle weight.

Did you mean increase in unsprung weight, Bill?

No, although this is also a factor.

I'm referring to the point that if you increase the wheel radius, but leave the brake drum size the same, there is a reduction in permissible axle weight. This can be significant. For example changing 14" rims for 16" rims, but leaving a 10" drum brake leads to a 200kg reduction in permissible axle weight.

[RHKTriton]

I'm wondering why you would go from an optimum scenario to a lesser one Darren?

For the last 40yrs or more people have been striving to go from steel to alloy. Bigger wheels/tyres would also increase drag at the van.

The typical motivation is to have a common wheel so less spare tyres need to be carried around. Just looking at your pic, try one of the alloys from the tri, as 5th suggested. If that fits, a better outcome would be simply to get a couple of preowned triton alloys and one spare can be used all round.

I've been looking at options for my 6x4 trailer and that'll need guard chopping, new axle and hubs. Then I'll end up with having a spare on board with tougher tyres on the trailer, in place of the retreaded car tyres.

[Duzzy]

The wheel and tyre on my Extremo Deluxe is LT 235/75 R15 with six studs. I'm extremely confused I have to say. My thinking was to have Roma's and tyres the same on camper and triton to give both an extra spare but I may be simpler to just buy an extra spare for each.

Regards Duzzy

[4wd26]

the offset is where you run into trouble, even if the stud pattern is the same.

the triton rims are +38 offset and like mentioned above the campers are usually zero or -10

this is a fair difference

The triton rims will most likely foul on the chassis if fitted to the camper (disregarding the centre bore of the triton rims is small and usually will not fit)

The camper rims on the triton will stick out beyond the guards

additionally diameter of the tyres, weight rating of the tyres and the rim strength load rating.


it can be done, I have done it sort of, the cheapest way out for me was to buy 4 rims and tyres for the camper in a zero offset and put on the same tyres as the triton.

I still used the factory rims and tyres on the triton.

theory was if I got a puncture on the triton I could use the factory spare

got a puncture on the camper use the spare

if I was unfortunate enough to get 2 punctures on the triton (and the camper was still good) I could use the 2 spare zero offset rims and tyres on the same axle to get me out of trouble.

you end up with carrying 3 spares, still run the factory rims and tyres (so save 5 new steel rims) and have redundancy if something goes really wrong.

I only carried this setup when going remote and think that you might need 2 spares of the triton or camper.

I was also lucky in that my trailer had 12" electric brakes so the larger rims and tyre diameter didn't make a noticable difference to the load rating of the van.


you will need additional steel wheel nuts

[Duzzy]

Thanks 4wd26, I'm unsure what to do, I have to say going from a small 4 cylinder Hyundai to a 4wd is such a massive learning curve. This all began after reading an article about going bush with alloys and how if you damage alloy it's hard if not impossible to repair vs steel that's fixable.

Regards Duzzy

[snakesoup]

don't believe everything you hear mate, chance are if you hit something hard enough to damage an alloy wheel you have probably damaged something else as well, the alloy wheels are bloody strong, more so genuine wheels, anything aftermarket is anyone's guess though, stick with the stock alloys and you will be fine, and you can probably say the same thing for the genuine steel wheels too, aftermarket stuff getting around is fairly low quality..