Pajero Owners Club of South Africa

Has anyone gone up from the standard 265 x 70 16's to the slightly larger 75 profiles? I am considering upsizing as I was very unhappy with my ground clearance (or lack thereof) on recent trip to the Kgalaghadi. Obviously I don't want to have the tyres cathing on anything - standard suspension at the moment. Planning to have air helpers fitted to rear in the future too.

Please submit feedback. Thanks, Gareth

I run 265 75 16 but I have suspension lift. I don't think they will rub anywhere even on std suspension and if they do it will only be at full tilt and compressed fully. The problem is more that they mess up your ratios on the gearbox and on an autobox makes it difficult to achieve lock up leading to higher box temp and consumption. On a manual like mine this is not a problem at all but they do rob some horsepower and your low gear is now slightly higher geared. It obviously also throws out the speedo slightly. Where the speedo was always about 10km optimistic it is now about spot on. This makes it appear as if fuel consumption deteriorate badly due to the seemingly 'lesser' distance covered by the larger circumference tyre.

CATS

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Thanks for the comments, Cats. Mine's an auto and I never thought about the gearbox lock-up side of things. How significant do you think this will be? According to my calculations the overall circumference of the wheel will increase from 2443.3 to 2526.5, i.e. by 83mm which is a 3.41% increase. So, if my thinking is correct, at any given GPS speed the wheels will be rotating ~ 3% fewer times with the 75 profile than they would have with the 70 profile. Similarly engine and gearbox rpm ~3% lower, assuming in the same gear and Torque converter in same status - which I suppose is the issue?

Now I'm really not sure whether to go for it or not

Best is to get someone with an auto to comment. I know for a fact
that some people run them on autos, but I have read that some people complain that the torque converter does not lock up as often as it should. You can possible overcome this with 4EPikanini's manual torque lockup kit if it is a problem?

Do search on this manual lockup kit if you do not know about it.

CATS

Hi GeeCee

I'm running 265 75 16. No problem with rubbing tyres, although, I do have a OME lift (bought the pajero with the lift and bigger tires fitted).I think CATS has a valid point, they will only rub on full lock, other than that, I don't think it should be a problem.

On the torque converter issue, I think I'm stupid, or just don't know any better, but I still can't find out when the converter locked up, I believe it happens round about 2000rpm?

MThompson wrote:Hi GeeCee

On the torque converter issue, I think I'm stupid, or just don't know any better, but I still can't find out when the converter locked up, I believe it happens round about 2000rpm?

A rough & ready description re lockup:
Say you are cruising along at about 105 - 110 km/h on a flat road. Your rev counter is showing about 2000 rpm. Then you nudge the accelerator or come to a slight incline and the revs go up to maybe 2200 - 2300 rpm with no change in road speed. The box has just gone from lockup mode (zero / very little slip) to slip (not lockup) mode. AFAIK this is controlled by the interaction between the engine and transmission ecus. At the electromechanical level it results in the activation / deactivation of the lockup solenoid on the auto box by the transmission ecu.

More heat is generated in the auto box when the box is not locked up.

The box more easily drops out of lockup in 5th than in 4th - that is why there are many recommendations to run the box in 4th when towing - especially on inclines or into headwinds.

I have a stock standard 2003 Gen 3 Auto DiD Pajero - 200,000 kms.
I have run 265/75 R16's for 120,000 kms and would recommend them to everyone.
I spoke to Michelin / BF Goodrich before deciding.
After 2 sets of BFG All-terrain T/A, I am now on Cooper S/T Maxx

Most of my mileage is high speed towing (110+kph) plus some unpaved roads/tracks.
There are no tyre clearance problems.
Ground clearance is improved.
I can't speak to the effect on fuel economy as I rely on the odometer for the calculations.
A bonus is the speedo is much closer to correct - now 100kph reads 101kph

I did have a gearbox failure, but that was related to a blocked radiator pipe (and mis-diagnosis by dealer).
Bob Guthrie
Sydney Australia

Thanks for your comments, Bob. I'm going for it
Just one last question; how are you finding the Coopers compared to the BFG's?

I've fitted 265x75x16's on both my 3.2 Did's - Bridgestone Dueller D694's.
I also have Firestone's Air Springs on one vehicle.

No issues with the 75's - can recommend them. I am not going to repeat the obvious advantages again. Slightly more sensitivity as fas as the torque converter / lock-up is concerned, but not really noticeable at higher speeds.

The slight increase in ground clearance from the higher (75) profile, is better than the increase from the Air Springs on my vehicle, but the increase is only around 11mm....not enough to for serious off-road work, just a bonus.

Regards
Charles

Hi, I upgraded my Std 265/65R17 tyres to 265/70R17. This gave me 2cm improvement in ground clearance. Power on tar is slight down on pull away if you like to drive fast, otherwise you would not notice. Fuel consumption is down from 9.5km/lit to 9.2/lit. Not bad at all. Did tierkloof 4x4 over december, had no rubbing. Very rocky. Never had hot transmission problems, also done thick sand at Buffelsfontein, no problems. 2005 DID