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Most of us aim to keep our tyres pumped somewhere near maker's recommendations, and we know that over- or under-inflation can lead to undesirable tyre wear. But I have never seen any indication of how far it is permissible to go from recommendation before that becomes significant - in other words a plus-or-minus figure. Any suggestions?
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I quite often read about HJ recommending a pressure drop of between 1 to 2 lbs lower than the minimum cold pressures to those who feel they have too harsh a ride.
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I quite often read about HJ recommending a pressure drop of between 1 to 2 lbs lower than the minimum cold pressures to those who feel they have too harsh a ride.
I never, ever, go below manufacturers' recommendation but usually experiment going up a little - my present car is 33/33 as standard but I run at 34 front 35 rear
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I quite often read about HJ recommending a pressure drop of between 1 to 2 lbs lower than the minimum cold pressures to those who feel they have too harsh a ride.
I don't think that would make a scrap of difference. My Audi tyres are more than 12psi higher than those of my harsher riding TR7. A foam cushion would be much more effective.
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i add 4extra on the front. 3 for the extra weight of auto and one for lighter steering
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Even at this time of the year my tpms tells me my pressure goes up 2psi when tyres warm up.
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I look at the tread wear. If I'm wearing the outside edges, I go up a couple of PSI.
On my landcruiser with proper all season tyres, the manufacturer recommendation was 29psi, but I ran them at 35 psi during the summer, 32 in winter. When I traded the car in after 40,000 miles on the tyres, the salesman commented that the tyres 'looked almost new'. They'd actually worn down from 11mm to 6mm. It helped that I'd rotated them every 10,000 or so, of course.
My current car is supposed to run at 34psi [cold], but the tyres wear more evenly at 36psi. The TPMS tells me that rises to 39-40 when they warm up.
Edited by NARU on 01/12/2018 at 07:36
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The much recommended Michelin Cross Climates are an XL rated tyre. As such most advice (but not HJ's) is that these should be run at about 10% over standard pressures. If you run them at normal pressures an XL tyre is rated at a lower load capacity than a standard load tyre.
In normal use I doubt it makes much difference but I run mine at plus 10% and would certainly not run them at pressures below the standard tyre figure.
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..after 40,000 miles on the tyres, the salesman commented that the tyres 'looked almost new'. They'd actually worn down from 11mm to 6mm. It helped that I'd rotated them every 10,000 or so, of course.
Please advise the tyre make which has >6mm tread depth after 40,000 miles on a heavy 4x4! ( I assume on tarmac, not snow). Also, what new tyre has a depth of 11mm?
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..after 40,000 miles on the tyres, the salesman commented that the tyres 'looked almost new'. They'd actually worn down from 11mm to 6mm. It helped that I'd rotated them every 10,000 or so, of course.
Please advise the tyre make which has >6mm tread depth after 40,000 miles on a heavy 4x4! ( I assume on tarmac, not snow). Also, what new tyre has a depth of 11mm?
If they are off road tyres, the depth can go up to as much as 17mm.
Read many reviews that the tyres on Land Cruisers last a long time.
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..after 40,000 miles on the tyres, the salesman commented that the tyres 'looked almost new'. They'd actually worn down from 11mm to 6mm. It helped that I'd rotated them every 10,000 or so, of course.
Please advise the tyre make which has >6mm tread depth after 40,000 miles on a heavy 4x4! ( I assume on tarmac, not snow). Also, what new tyre has a depth of 11mm?
To be fair, my Mazda 3's OEM tyres (awful Bridgestone ER30s - noisy, firm riding, eventually very hairy in the wet - fine handling in the dry) were at 3-4mm on the fronts and 5mm or so on the rears after 40k miles and 6.5 years of use, though mainly on faster flowing roads.
Technically I could've got another 20k out of them, assuming I didn't end up in a ditch when it rained. My last set of tyres (Dunlop SP Sport Fastresponse) replaced in the Spring were at 25k/5.5yo but had only worn down to 4-5mm on the fronts and 5-6mm on the rears and were only changed because it was cheaper to do so as I had to change the alloys due to corrosion and downsixing both from 16in to 15in was far cheaper over the longer term.
I'd say I could've got another 15k out of them had the alloy corrosion (also causing the tyres to leak air) not been a problem. My latest set of CC+'s will be rotated every 10k/2yrs (I didn't bother with the previous sets - perhaps I should've done) to get more life out of them, given they seemingly have been designed for longevity in mind.
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John F, Lots of full size 4x4 tyres last well in excess of the mileages mentioned, they are seriously big tyres, probably half way between lorry and car sizes, and it's not unusual to get 200,000+ kms out of premium make lorry tyres on a drive axle, more if the vehicle is on light loads and/or well driven.
The current set on my Landcruiser came with a measly 9mm (road biased snowflake marked all seasons), the new set i put on my last one had around 13mm (full all terrain jobbies).
BFGoodrich AT's regularly get spoken of with 70+k miles of mixed use on full size 4x4's, but they do start off with 12 or more mm of tread, snowflake marked to boot, expensive tyre though.
Edited by gordonbennet on 01/12/2018 at 18:33
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Lots of full size 4x4 tyres last well in excess of the mileages mentioned, they are seriously big tyres, probably half way between lorry and car sizes, and it's not unusual to get 200,000+ kms out of premium make lorry tyres on a drive axle, more if the vehicle is on light loads and/or well driven.
GB, part of that will be due simply to the larger rolling diameter of a lorry tyre, meaning that any patch of the tyre meets the road surface less often than on a smaller wheel. And perhaps (I don't know) lorries scuff round roundabouts less vigorously than many cars ?
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Thanks, gb - v interesting. And indeed v expensive - twice as much as an ordinary tyre. Would look a bit odd on a Focus.
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