Should the tyres be inflated to full or half load if you are driving half load most of the time, but occasionally have a full load?

ie which causes more tyre wear or is safer?

If you got have a "full load" on, you should consider either taking a cab or getting a designated driver.

Seriously, ALWAYS run the full recommend pressure unless you're stuck or about to go "sandy".

Hi,

I generally inflate the tyres slightly above recommendation (38 - 40 psi). Handling seems to be improved, fuel economy is slightly better, and ride is fine.

Uneven wear is obviously an issue to be considered (pressure too high will wear the tread in the middle) but 38 - 40 seems fine.

Hope this helps.

Seeya,
Michael

If it's just occasional full-load use and for short periods of time, I leave the pressure set at half-load. Any additional tyre wear for short periods would be neglible. :)

I only ask because when I got the car new it was inflated to FULL LOAD specs. When I checked it at the servo, I inflated it to half load and it seemed that the ride was not as good.

So I was thinking, in Australia with the blistering summer heat, it may work out a good compromise to inflate to full load during winter and half during summer as these are "cold" pressures. Anyone have some thoughts on this?

I have always inflated tyres to the maximum specified pressure for over 40 years with no problems. I find the tyres last longer, the car has more precise handling and the difference in ride to that with lower tyre pressures is negligible.

The main justification for using minimum specified tyre pressures has been to give a softer ride especially on pot-holed roads. If you drive regularly on unsealed roads, there is a tendency for more sidewall damage if the tyre pressures are on the low side - as I do a lot of unsealed road driving, I always use the maximum pressure specified for high-speed driving for this reason.

I only ask because when I got the car new it was inflated to FULL LOAD specs. When I checked it at the servo, I inflated it to half load and it seemed that the ride was not as good.

So I was thinking, in Australia with the blistering summer heat, it may work out a good compromise to inflate to full load during winter and half during summer as these are "cold" pressures. Anyone have some thoughts on this?

Hi midician,

I think it is important to understand what "cold" actually means.

It does not refer to ambient temperature but to the fact that there has not been a load on the tyre, i.e. it has not been driven. The tyre will warm up while driving, and pressure will increase. Probably more so for a tyre that is "underinflated" simply because there will be more internal friction.

Whether you adjust your pressure to 38 psi at 5 deg.C or at 40 deg.C, you still will have 38 psi.

Of course if you adjust the pressure to 38 at 5 deg.C, and then within 10 mins the temp increases to 40 the tyre pressure will go up. I suppose that even in Adelaide you won't get that sort of rapid change in temp.

Simply adjust the pressure to your preferred value at the current ambient temp, and you'll be OK.

If you intend to use your Eos as a truck (i.e. with a full load) simply increase the pressure (again, with "cold" tyres) until such time when you drive it all by yourself.

Hope this makes sense.

As mentioned previously, I prefer to run my tyres at 38 - 40 psi year-round, simply because the handling seems to be better, the fuel economy seems to be better, and the ride quality does not seem to be affected. See also silvershadow's post!

Regards,
Michael

I just did a check , and for every 10 degrees change in temperature, tyre air pressure changes approximately 7 kpa (or 1 PSI) . So if you inflated your tyres at 5 degrees on a cold morning, then in 35 degree summer your tyres could be 21kpa over or 3 PSI, which isnt that much really. That puts some perspective on my summer-winter theory . The consensus appears to be to use full load pressures. Thanks to all who contributed !