For jonceebee, I've only done 5k miles with the Nitrogen fill & not needed a top-up yet, on the Pirellis. I've done more than 8k miles in total on the Nokian winter boots (this Yeti & previous one, owned 2 years & 24k miles) & not needed anything there either. One thing I have noticed is that the pressures remain constant whatever the season, this checked using the very good digital gauge used by the guy who did the Nitrogen filling. He's a local independent garage who also fits tyres under a franchise with one of the major on-line suppliers, through whom I sourced the Nokians.

Cheers.

Thanks for the info and you seem happy with Nitrogen and there is obviously an advantage in keeping pressures over a period of time. I have noted a previous post regarding the ride being compromised on the 17" wheels do you have any comments to confirm this?

I have found that the ride is a bit harder which is due to the pure Nitrogen fill but also maybe associated with the fact that air is likely to contain more moisture. This may also contribute to the increase in tyre life, as dry Nitrogen will not penetrate the compound & cause corrosion within the tyre carcase. However, as we witness in F1 these days, tyres are designed to undergo massive degradation, so I'm guessing that tyre manufacturers engineer their compounds to offer acceptable grip under all conditions, but at the expense of longevity. Their aim, obviously is to make a tyre that, under general useage, offers reasonable traction & handling characteristics, but isn't going to last for years, as they need us to replace our boots at regular intervals, maximising their turnover & profits. A bit cynical, I don't think so !! So, my guess is that my tyres are likely to wear down to the minimum tread depth long before I have noticed any deterioration of any other aspect of the tyre design or life.

Not too long ago, an MOT fail point was cracked sidewalls, but these days, tyres wear & need replacing long before they are old enough to degrade to the point of having cracks appear. I used to run a Mini or two (old style) & a few Citroens of various models (Visa, BX, Xantia) & always used Michelin tyres. They lasted for well over 35k miles on the front before I replaced them.I don't remember having to renew rears, they lasted well over 50k miles. Dry grip was fantastic, but I always treated them with a bit of respect in the wet, as then, the compound was a bit on the hard side to get dry mileage, although they never threw me off the road & over the dike.

Their aim, obviously is to make a tyre that, under general useage, offers reasonable traction & handling characteristics, but isn't going to last for years, as they need us to replace our boots at regular intervals, maximising their turnover & profits. A bit cynical, I don't think so !! So, my guess is that my tyres are likely to wear down to the minimum tread depth long before I have noticed any deterioration of any other aspect of the tyre design or life.

Not too long ago, an MOT fail point was cracked sidewalls, but these days, tyres wear & need replacing long before they are old enough to degrade to the point of having cracks appear.

I disagree with all of this. Don't have time for a detailed argument at present, but my experience of tyres just does not bear out what you say. If you had several cars, so that you did only a few thousand miles per year in each, you would be throwing away tyres long before the tread was worn out.

I think I agree with r999.

Caravan (and car) tyres are now recommended to be changed after 5 years, because in that time the rubber will have "hardened" mostly due to UV "contamination", flats will have formed where they have been stood on without movement, and cracks will appear in the rubber naturally. I doubt that sticking nitrogen in them is going to stop any of those problems as they are mostly exterior.

One trick I've always used & passed on from dad, is if at a garage your tyres most likely wont be near the 'cold' temps on the filler cap. So take these an add 3psi. So 32 becomes 35 etc etc. Used this on cars for many years without any issues and means you can check them at any time.

As mentioned the digital gauges at garages are subject to testing, so are going to be much more accurate than anything you'll use on the driveway.

I've read all the comments re. tyre pressures & longevity, but return to one of my points, in that, unless you only cover a very small annual mileage, due to the inherent maker's compound chemistry etc. your tyres will have to be replaced long before they show any signs of deterioration due to exposure to UV, ingress of moisture into the carcass. Who can hold up their hand & honestly say that they have any tyres more than 5 years old?

The annual mileage most of us cover these days means we'll have replaced them on a regular basis, unless, as I commented, I was getting around 50k miles from Michelins fitted to the back end of front wheel drive cars, but even then ( & that was quite a few years ago), I never saw any signs of cracking or breakdown. Tyre design, profiles & the chemistry involved now has changed considerably.

If all tyre manufacturers thought along similar lines, all tyres would look & perform the same, a bit like cars themselves, really, due to crash performance & that sort of thing. They obviously have to compromise on design, compounds etc, as, apart from a very few specialised tyres, they have to design something that is suitable for a variety of makes, models & conditions.

If we wanted the best dry grip, traction & mileage, we would all be using hard compound racing slicks, if they were legal. If we wanted the best wet weather performance, we'd all have hand-cut soft compound wets or intermediates, which would last a few hundred miles

My mean annual mileage over the last 10 years is around 12k, so as I've only been getting around 28k to 30k miles per front set, I have been replacing tyres on a pretty regular basis, long before I've seen any deterioration, or fallen outwith the 5 year time limit. I've no idea when I'll have to renew the tyres on the Yeti, it's mostly in front wheel drive mode, very rarely in 4wd, as far I can tell. An indicator to tell us when the rear diff is engaged would be a neat idea.

When I removed the standard rubber I marked them front/rear to make sure they're replaced correctly, so I can get an idea what the life will be.

My last Yeti (140 Elegance) was sold with 25k miles up, 2.7mm tread left all round on Dunlop SP Sports, but I didn't mark them when changing over to Nokian winter-wear, so no real idea of life expectancy.

Cheers, thanks for all your comments.

Who can hold up their hand & honestly say that they have any tyres more than 5 years old?

Not on my car but have one on my van that is now 10yrs old, it was the spare stored under the van, and its still sound (just past an MOT) . It was fitted with Goodyears from new .

Could do with tyres that last like the van ones 60k out of the fronts 70k from the rears. Although the Goodyear 4 seasons I have on the yeti are wearing well, fronts I think should do around 24k at current rate of wear, then rears moved to the front and new on the back, so the rears should be pushing towards 30k before they are approaching the limit.

Who can hold up their hand & honestly say that they have any tyres more than 5 years old?

I can't at present think of a time in the last 10 to 12 years when I have not had several tyres more than 5 years old.

My apologies for resurrecting this thread, but I would like to get a few comments please. I read on some earlier threads some members have had as much as 36psi in their tyres. I tried 34 psi but found the ride to be choppy. I dropped the pressure to 30psi and the ride is much, much better. What was the supposed advantage of the higher pressures and as the ride seems better with a lower rate what would we assume would be the safest to drop down too without problems?

I recently swapped from winter tyres (running 2.4 bar/36 psi) back to summer tyres. As we were due to go on holiday not long afterwards, and would have a full complement of people & luggage (including the roofbox) I put the pressures up to 36/2.4 front and 44/3.0 rear. I had a few days driving on my own with those pressures and the ride felt little different to the winters (which had been a softer ride). It was only when I dropped the pressures back to the unladen setting (32/2.2 all round) that bumps in the road became more noticeable. It's not so much that the ride was softer but it was smoother, if that makes any sense.

That seems contrary to what I'd expect, and I've been looking to see what the issues are with running higher tyre pressures. It's not like they balloon out at that level, so I can't see the contact patch being greatly reduced as a result. I'm inclined to put them back up to the winter setting and maybe slightly higher at the back and see what difference that makes.

On the plus side if you over inflate by 20% it means when the oxygen seeps out through the rubber you have your now nitrogen filled tyres at the right pressure!

As an aside I have noticed that fuel consumption has gone up since putting the heavier 17s back on the car. It ran at around 39/40 until fitting winters when it averaged 41/42 and now it's back to 40. The winters are slightly smaller (205/55/16s instead of 215/60/16s) but I took the difference into account when doing the mileages.

When I refitted my summer continental ecocontact 2s the mpg improved by 1 to 2 mpg.

My summers and winter contis are the same size 205/55/16.

32 psi or 2.2 bar is fine.

Just as it has to be.

Most pressure gauges are not worth buying because they are inaccurate.

Last week I got an Italian manufacturers Michelin certified gauge and it cost me a packet.

80 Euros to be exact but is 100% accurate .

For me it is money well spent,as it will keep my family and myself safe, and will prolong the tire life as they will never again be over or under inflated.

Edited 24 April, 201313 yr by oriki

Good, I will settle for 32psi then, it actually feels good over the bumps. The dealers I have found always seem to put about 5psi above the recommended figures and I have regularly had to deflate them when my Octavia goes in for service. I have purchased a Michelin rapid inflator and the gauge seems reliable when making comparisons figure wise. Thanks for your comments

On 11/03/2013 at 18:46, Truthseeker said:

Yep - 225/50/17's @ 32lbs all round.

After reading about other similar cars similarly shod all being 32psi all round, I checked mine today for the very first time after just over two month's of ownership. Eeekk! 37 psi all round. This is I suppose the Economy setting that the supplying dealer settled on. It will be boosting my mpg, but can't have helped in the recent frozen  snow. They are at 32 now. 

Your worried, mine was delivered at over 50psi, and I drove it home 30 miles like that. Thought I had made a mistake as the ride was so hard!

 

When the car is made the tyres are overinflated deliberately.

This helps to seal the bead to the rim, and it also avoids the tyre getting flat spots as it could be stood stationary for months whilst stored for delivery.

As part of the pre-delivery inspection the tyres should be let down to the right pressure.

They tend to deliver or service cars though using the fully loaded pressure, as they have no idea how you will use it after driving away.

Edited 10 January, 20188 yr by kenfowler3966

I've seen numerous mentions of the issue being with 17" rims but that's what I have and too be honest, my snow monster sticks to the road like glue. I can't fault it.

 

I do however, use a decent pressure gauge and foot pump to put 32.5 PSI in the tyres when they are cold.