Thread: Low Profile Tyre Issues

Hi Bob. I've got a D4 same year and had no probs. even with the standard tyres on which Cook and I did a good few kays of dirt. Only real probs. were in sand.... very embarrassing.
I changed them for Maxxis 980s LT at about 38K and again have had no trouble and have done the Skull Springs Road which had plenty of rough stuff on it and we towed the van as well.
Next weekend we'll be on the beaches down south and I'm hoping to get a bit more experience of driving on it.
Never had a prob. before in the Defenders or even the Prado.......
AlanH.

In my opinion the advice you have been given is not quite right. You still need to reduce pressures on low profile tyres, just not as much as you would a higher profile tyre.

I ran the Coopers on my D4 and to be honest I don’t think they were very good, although probably the best choice I had at the time. I think their carcass is a little on the weak side. I also think the tread design is a problem. The grooves are relatively wide compared to the depth of the tread meaning the weak carcass is vulnerable to sharp rocks getting between the tread blocks and penetrating it.

That said I never had problems with punctures in the bit of outback touring I did in the D4, or when off-road. All my punctures (and there were a few) occurred at highway pressures - both on dirt and bitumen.

The trick with the tyre pressures was to reduce them enough to enable the tread to flex over rocks but no so much that the sidewalls became exposed. My rule of thumb was to reduce pressures by 4-6psi when hitting the dirt and keeping the speeds down to something sensible, like you were doing.

This seemed to work well for me, but changing to 18”s is a much better idea.

Cheers,
Jon

Last year we did Melbourne to Broom, GRR to Katherine, Kakadu, Darwin, Lytchfield, Materanka, Lorrella Springs, Alice Springs, West Donald Rangers and home. 15000 km, about 5000 on dirt, 18 inch Tuff Ant with 265 65 BFG AT2 . Reduced tire pressures as needed not one puncture not even a scratch in the side walls. Well worth the investment
19's are OK but not ideal and Coopers are a crap tire IMO anyway, I have them on my 19's and don't rate them well. Go into a tire shop and give the side walls a pock with your finger, very soft and not much in them compared to a good AT

I have switched my fronts to the Maxxis 980 LT in the 19” size. The tears are still the Coopers but waiting for them to wear down enough to replace with Maxxis. The Maxxis seem far more robust in the sidewall, which is kind of the point of the LT rating.

I don’t do enough to warrant 18” at this stage.

Originally Posted by ATH

Hi Bob. I've got a D4 same year and had no probs. even with the standard tyres on which Cook and I did a good few kays of dirt. Only real probs. were in sand.... very embarrassing.
I changed them for Maxxis 980s LT at about 38K and again have had no trouble and have done the Skull Springs Road which had plenty of rough stuff on it and we towed the van as well.
Next weekend we'll be on the beaches down south and I'm hoping to get a bit more experience of driving on it.
Never had a prob. before in the Defenders or even the Prado.......
AlanH.

Hi Alan

Thank you for replying. I am encouraged by hearing that you had no problems in the rough stuff. I note your comment about being happy with the Maxxis 980s. I had seen them on a Discovery 5 and its owner also recommended to me. I have tagged the Maxxis as a good option to test.

Cheers
Bob

Originally Posted by jon3950

In my opinion the advice you have been given is not quite right. You still need to reduce pressures on low profile tyres, just not as much as you would a higher profile tyre.

I ran the Coopers on my D4 and to be honest I don’t think they were very good, although probably the best choice I had at the time. I think their carcass is a little on the weak side. I also think the tread design is a problem. The grooves are relatively wide compared to the depth of the tread meaning the weak carcass is vulnerable to sharp rocks getting between the tread blocks and penetrating it.

That said I never had problems with punctures in the bit of outback touring I did in the D4, or when off-road. All my punctures (and there were a few) occurred at highway pressures - both on dirt and bitumen.

The trick with the tyre pressures was to reduce them enough to enable the tread to flex over rocks but no so much that the sidewalls became exposed. My rule of thumb was to reduce pressures by 4-6psi when hitting the dirt and keeping the speeds down to something sensible, like you were doing.

This seemed to work well for me, but changing to 18”s is a much better idea.

Cheers,
Jon

Hi Jon

Thank you for your comments. What you said about the sidewalls makes sense. When I was told not to reduce pressures, the reason given was that it increases the risk of side walls being pieced by sharp rocks.

Cheers
Bob

Originally Posted by discomatt69

Last year we did Melbourne to Broom, GRR to Katherine, Kakadu, Darwin, Lytchfield, Materanka, Lorrella Springs, Alice Springs, West Donald Rangers and home. 15000 km, about 5000 on dirt, 18 inch Tuff Ant with 265 65 BFG AT2 . Reduced tire pressures as needed not one puncture not even a scratch in the side walls. Well worth the investment
19's are OK but not ideal and Coopers are a crap tire IMO anyway, I have them on my 19's and don't rate them well. Go into a tire shop and give the side walls a pock with your finger, very soft and not much in them compared to a good AT

Hi Discomatt69

I think the country you saw last year is spectacular.

It is interesting to see that you have Tuff Ant rims with 265 65 tyres and good to see that they have not let you down. It is an attractive option and am I grateful for your comments.

Does a 18" spare with the 265 65 BFG AT2 fit into the area underneath the car for the spare wheel? I saw that you carry spares on the back and am wondering if you get sick of swinging the wheels out of the way to get access to stuff in the back of the car?

I assume that when the 18" rims are on, your actual speed when the speedo reports 100kph is different to what it would be with the 19" rims and 255 55 tyres. If this is the case, do you have a feel for the size of the variation?

Cheers
Bob

Originally Posted by DiscoJeffster

I have switched my fronts to the Maxxis 980 LT in the 19” size. The tears are still the Coopers but waiting for them to wear down enough to replace with Maxxis. The Maxxis seem far more robust in the sidewall, which is kind of the point of the LT rating.

I don’t do enough to warrant 18” at this stage.

Hi DiscoJeffster

Your positive comments about the Maxxis 980 LT is very helpful.

Cheers
Bob