The standard tyre pressure recommendations of all the 4WD Yeti's are essentially the same 2.2 bar all round for less than full load and 2.4 front and 3.0 rear for full load. (The anomaly is the 3.1 recommendation for the 81 kW rear at full load on 16" tyres)

The recommendation from Skoda (and others) is to increase the pressure by 0.2 bar for winter tyres.

My practice is to run 2.4 Bar all round in Summer and 2.6 Bar in winter with winter tyres. The numbers were similar for the Octy and the same practice seemed to balance handling and tyre wear well. The slightly higher than recommended pressure reducues rolling resistance a little and does not seem detrimental to handling.

I have faithfully increased the pressure in Winter for winter tyres, but I am not sure I really understand the logic behind this?

I start out with new tyres and switch them front to back during change from summer to winter etc. After the first season, the rear tyres are less worn, so they go on the front. after a little, they are equal, and at the end of the period, the rear are the better set.

ADAC and other "safety" organisations insist on "the better tyres" go on the back. If you do that, you cannot switch the tyres to even wear, and end up with front tyres worn out and the rear being different from the new tyres of the same brand, as technology has progressed. Since the front tyres do the most work, they ought to be the better ones. The old philosophy that half a millimeter of extra thread on the rear is going to save your kiester in the oh-so-dangerous rear wheel skid is a lot of bunk.

So, what do you think?

I believe that the reason why winter tyres or even tyres in winter, need to be at least up to pressure is:

a, to maintain the minimum tyre crown area on the road/ice interface so maximizing ground pressure on ice or in snow so enhancing grip,

,b, to prevent any unwanted flex in the tyre, so making handling absolutely predictable and removing any inertia effect that soft flexing tyres present, that is it removes any wooly feeling and over corrections. The last thing that is wanted in bad conditions is unpredictability.

The reason why some advice is to always put the least worn tyre on the back is to help prevent oversteer by preventing the tail/rear end of the car slipping. It is felt that it is safer with plough on oversteer as most people instinctively back off while many do the wrong thing with oversteer. Manufacturers have for years built in understeer even into rear-wheel drive vehicles because it is felt generally safer for most people. Psychologically it is disturbing when the front does not go where it is pointed so most people slow down and and the cars handling characteristics are designed to handle then in a predictable safe manor. More experienced drivers might prefer a neutral or even a mild tail happy or oversteering car.

We might feel that it is instinctive to put the best tyres on the front. This might be because the majority of cars over recent years are FWD so it makes sense to put the best on the hardest working axle particularly as it does the steering but as I have said above tis might promote oversteer. Rear wheel drive vehicles of old tended towards oversteer because the rear end will step out under-power and then fish tail when backed off too rapidly. So often rear wheel drive vehicles of old had chains on the back though some did promote chains on the front because of steering. From memory it was thought best to circulate tyres with the spare on older rear wheel drive cars. I do not know what the policy is for new rear wheel drive cars.

I would be tempted to follow manufacturers recommendations, as they have most likely done lots of tests. Only d differently perhaps if you know what exact effect your after, that is to change the handling characteristics differently from that which the manufacturers have inbuilt into the car.

I suspect the increase is recommended for the reasons given here:

My link

Hope this link works and that the information helps.

I suspect the increase is recommended for the reasons given here:

My link

Hope this link works and that the information helps.

Thanks, the link works and it sounds reasonable. My practice is to always run the tyre pressures a little high - plus 2 psig or 0.15 bar. On planned longer trip even a little higher.

What it is saying is tat the tyres should be checked at the ambient temperature in which they are operated. No need to put additional pressure up if it is correct at that temperature otherwise they will be overinflated.

So if your driving in a hot country does one do the same. In the past tyre company advice was to check tyre pressures in the early morning before the tyres had time to warm up. The implication was that pressures would rise as temperature rose and that this of course was normal. I wonder if tyre pressure advice has changed then. Tyre pressures and temperatures also increase as we drive and the harder we drive the greater will be the increase up to a point.

Anthony -I agree with all you have said, and I do not think the practice or principles have changed.

In winter, I suppose the cold weather and maybe snow and wet cool the tyres a bit better, so they do not get as warm from driving - relatively speaking - and therefore the additional 2 psig are recommended.

It is quite clearly wrong to check pressures in a warm garage and then expect that pressure to be ok outside in -5°C.

A little excess pressure doesn't hurt and reducues the rolling resistance and heating a little. Key word here is "little"

Interetingly, every time the car has been in the garage for service, it always comes back with tyres inflated to the maximum for the maximum load. Too much in my opinium, as it is very infrequent that the rear is fully loaded. I ran the Octy estate on the same principles - a littel overpressure and the same pressure in all 4 tyres. Over 120,000 km, the tyres wore very evenly with no unsual wer patterns. Rotated summer/winter every year and put the best always on the front - this might induce some discussion. My reasnig is that the fronts wear more, so midway through the period, they are evenly worn and late in the period the rears are better. The result is even tyre wear on all 4 and always the same tyres on all 4, as they get replaced all at the same time.

This is my story, and I am sticking to it.

Edited 24 January, 201016 yr by Agerbundsen

I do not think that the Information given by the Michelin Tyre Company is qualified enough. It is over simplified and generalised. If a tyre is kept in a warm garage, then it stands to reason that the tyre will loose pressure. I beleive that it is this scenario that they are attempting to rectify

My link

"

Ambient temperature has an affect on tyre pressure. As the temperature drops, so the tyre pressure registered on a pressure gauge decreases.

For example, if a tyre is inflated to 2 bar (29psi) at an ambient temperature of 20°C, the pressure may only read 1.8 bar (26psi) at an ambient temperature of 0°C.

Your tyre pressures should be set to the vehicle manufacturer’s recommendations for the conditions in which you are driving. So, if your tyre pressures are reading low when you check them in a low outside temperature, then re-inflate them to the vehicle manufacturers’ recommendations.

Our advice:

When setting your pressures with cold tyres (tyre temperature at the outside ambient temperature), set them to the vehicle manufacturers’ recommended pressures.

In winter, if you set your pressures in a warm garage or workshop, add 0.2 bar (3psi) to the vehicle manufacturers’ recommended pressures to compensate for the 'cold temperature' effect to ensure that whilst on the road you run at the correct pressures."

They are not saying in winter tyres should be over pressure