Help with tyre size

[spnk]

Hi everyone!

Recently bought a LC j9 Challenger from a Dutch farmer. It's a factory-built LKW (Light Commercial Vehicle), and yes, it has three doors, two seats, and the back is just space for cargo. I believe the "Challenger" is the commercial name for this model in Europe, but correct me if I'm wrong.
Came with 265/70/r16 AT tyres, and now I want to get a set of winter ones, and anyway the front pair needs to be changed as they got only a few mm of tread left.
Been trying to find information on the web about possible variations of sizes, and all I found is that the standard ones are 215/80/r16, or as an alternative you can go for the ones that I have now.
From your experience and knowledge, what would be the best recommendations for mostly snowy and icy asphalt use, with occasional driving on snowy gravel and forest roads? Are there any other sizes that would be a good choice? Will be driving it mostly in the north of Finland and Sweden, at least for this winter.
Found a set of used 265/70/r16's, and still in good condition, but I know that the wider the tyres, the higher the fuel consumption, so I'm thinking about going for something narrower. Of course, I could just go and get the 215/80/r16's from a shop, but can't really afford new ones right now, so I'll just have to settle with what the local used tyres market has to offer.

 

[diggerdave]

This is one of those debates that will go on for ever.

First off, I think that any fuel saving will be trivial and only likely to be of relevance if you do a colossal annual mileage on roads, nor do I think there will be much difference in tarmac manners between the two (both were specified by Toyota when new after all).

So the only question is whether narrow or wide is best in snow or mud? Some say narrow cuts through to more solid material below, others say that wide 'floats' over soft material. I've read off road expedition books from the late 60s and the same debate was raging then too. I've tried both approaches - most recently replacing 265/75/16 with 235/85/16 and I have no idea which is best!

I strongly suspect that everything within a certain middle range is as good as anything else, and it's only at the more extreme ends (much more extreme than we're talking about here) of the range that you would notice any real-world difference.

 

[diggerdave]

P.s. I find this tyre size comparison tool useful as it visualises the different sizes and also works out useful stuff like the effect on your speedo of changing size.

http://www.kouki.co.uk/utilities/visual-tyre-size-calculator

 

[Xena]

You can also try this site, for comparison

https://tiresize.com/comparison/

Your current 265/70 is much wider and taller and would register slightly faster on the speedo than the 215/80

 

[spnk]

Thanks Dave and Xena! Already decided to go for the same size as I have now, and see how it goes, but your websites are already saved in my bookmarks. Useful stuff!

 

[Shayne]

285/75 R16 put my 90's speedo accurate though you will need alternative size wheels and other modifications to fit these .

 

[Xena]

Hi Shayne. . . now that you mentioned it, running on 265/75/16's the GPS says I'm cruising at 100KPH while the actual speedo says I'm at 110KPH. . . . no issues for me here.
Its just that I'm sooooo tempted to go 285/75/16 for that bad boy offroader look or a 275/70/17 for that bling look

 

[Shayne]

Far be it from me to say do it do it do it , oh no i wouldn't encourage anyone to jump onto the slippery slope of modification

did i say do it

 

[GeekOKent]

235/85/r16 - i like the way they feel on the road, in the snow and in the wet and very wet. In the mud not so much. I tried 255's and 275 before settling on the 235's. the 255 look right though. the 235's are a bit narrow. I can only imagine the 215 are really skinny (?)

 

[Beau]

Just a thought, but surely when you go narrow (say a 235) you have the benefit of a skinny tire when best needed but when off road (mud/snow) you can air down IF needed and gain that wider track tyre? Obviously you can't really do the opposite starting with a wider tyre?

Also I personally found tyre width didn't affect MPG noticeably. What did change it marginally was poking a good inch or two out of the wheel arch. Added air resistance I guess?

 

[GeekOKent]

Just a thought, but surely when you go narrow (say a 235) you have the benefit of a skinny tire when best needed but when off road (mud/snow) you can air down IF needed and gain that wider track tyre? Obviously you can't really do the opposite starting with a wider tyre?

agree; the 235's have worked well for me on the 105, so far; and added benefit is that they are available easily around the world, thanks to the size being the norm on a few other 4x4's

 

[spnk]

Hm. Some interesting thoughts on the 235 size here. I think I will give it a try next time when I get a new set of summer tires. So far, the "new" 265's are doing great! Love it how the car handles this Finnish black ice, which is one hell of a treacherous bastard, if you're not wearing studded tires!!

 

[diggerdave]

Just a thought, but surely when you go narrow (say a 235) you have the benefit of a skinny tire when best needed but when off road (mud/snow) you can air down IF needed and gain that wider track tyre? Obviously you can't really do the opposite starting with a wider tyre?

It's a good point Beau. In the UK there's no real tradition of 'airing down' (at least among green laners). UK lanes are quite short, so a day of laning is spent swapping and changing between tarmac and dirt. It is a massive pain in the proverbials to have to deflate and reflate multiple times.

Obviously its a useful thing to be able to do if you're stuck, but even then I suspect it would be low down the list of most people's options. You're more likely to find a winch than an on-board compressor in the UK!

 

[MarkW]

Airing frown doesn’t give you more width for traction, it gives more length. Bit like a caterpillar track

 

[tim falce]

My FX comes with 215.80x16 as standard but they are quite hard to get in a decent off road tyre now so I've gone for 225.75x16 Cooper M+S tyres which aren't too bad. For some reason Toyota didn't changed the speedo gearing on this model so with the 215s the speedo over reads by about 10% and a bit more with the 225s.