[ohlins]

As stated in the subject heading....

I have 4 nearly new General Grabber TR's 235/85x16 tyres on my Discovery 1.....(and one new spare)

I now have a 2003 auto Pajero which will need tyres within the next couple of months... I was wondering if these tyres would annoy the auto box in any way. I did find a great difference when I first put them on the Disco...slower acceleration compared to standard and the same fuel consumption as I had to keep her lit to get up to the same traffic speeds....After searching I find that most people go for 285's.....

The tyres work well in mixed conditions (even mud)and have a deep treat pattern....they performed with great results in the snow last year in the French Alpes.(very impressed indeed) They're a smooth running tyre and I would like advice if these can be used...(if not they stay on the Disco which will only be used periodically,and I bill myself for 4 new 265 tyres)...ho hum

I will be using the Mitsi as a road car for family holidays to the likes of Italy this summer fully loaded with camping kit and 1 wife and 3 annoying teenagers...so lots of steep,high mountain passes...it will not be off roading accept to enter the odd muddy/snowy field with my off road moto.

Any inmates have any thoughts?

Thanks in advance...

[tonton]

Ohlins,

The 85 refers to the height of the tyre wall as a % of the width of the tyre - therefore, the narrower you go, the higher the % needs to be to ensure the same circumference. You will find that the wider tyres often come with a 70 or 75 tyre wall.

It may be worth your while to measure the circumference of your tyres with wider ones. Normally one can go slightly up from the standard, and still get good performance and a more accurate odometer reading (which are usually reading conservatively).

Wider tyres are better in sand (which we have lots of in our play-pens) and in mud and snow, while narrower tyres should give you better fuel consumption.

Regards,
Anton

[ohlins]

Thanks for that information TonTon....

I had been using these tyres with the Disco,manual box and was wondering if any inmate here had any reservations about using same with the auto box.....

[Gerrit Loubser]

The Pajero's standard tyre size is 265/70R16 (if it is a GLS spec vehicle), which means that the tyre outside diameter is nominally 30.6". Now the 235/85R16 tyres have a nominal diameter of 31.7", which is around 3.7% larger than standard. In many cases this would have very little effect, but the DiD auto has very tall gearing and fitting bigger tyres could mean that your fuel economy is quite significantly affected, as the transmission will be unable to remain in lock-up mode in 5th gear for as much of the time. If you are able to cruise at very high speeds this will be less of an issue. I doubt whether any transmission damage would result, but the economy effect has been reported by some who fitted 265/75R16 tyres (nominal diameter 31.6") instead of the standard size tyres.

[JohanV]

what Gerrit said

[ohlins]

Thanks dudes for the response....very informative for sure...

I will need tyres on the rear in about a month...and in about 3 months on the front.

Based on the info I suppose I could brim the tank at the end of my current tank,and drive around as normal and take a reading on my consumption with standard tyres....

I could then organise,with my buddy who has a tyre changing machine,to mount the 235's and take another reading on my consumption after the next tank full.

I was thinking because I have the tyres already and they have loads of tread left,that I can at least try and mount them even if it's just to see what they're like.....bearing in mind that I'll have to buy 4 new ones if I did'nt do the change.....

If there was a probable difference in economy,I would have to off set that same difference with the price of a new set of tyres...and how long would it be before I arrived at that new tyre price...probably just by the time the 235's were used up!!

Any of this make sense??

Anyway...If there's a strain on the transmission then I can just put the tyres back on the LR and carry on as usual.....

As an aside we sit on the auto routes here at 130km/h all day and I suppose a test there will see if the autobox slips or whines like a banshee...I just needed some ideas as the whether even to go ahead with the change so as not to waste my time...heading off to Italy then back into France in July and just need to get it right

[tonton]

Ohlins,

I would not be too worried about the box - they are really rugged, and can take a lot of load, and the tyre sizes mentioned are not out of reasonable spec.

I would not have different size tyres on front vs rear, though - that will hurt your car if you putr it in 4WD.

Anton

[ohlins]

OK Ton Ton...

Thanks for that...

In the meantime if any other inmate cares to chime in with experience of what I'm going to try..by all means fire away...

I'll get the LR on 4 axle stands and get the tyres ready within the next few weeks....

(Now...what next to do..oil sensor or chain tensioner... lol )

[4ePikanini]

(Now...what next to do..oil sensor or chain tensioner... lol )

Both. They are cheap and pretty easy DIY. A failure of either can cost you the engine.

[ohlins]

Yip...no doubt....

I can do them both for sure...

Any one know the part numbers off hand??....no big problem...


Failing that I can just call a dealer....