I'm looking for a straight answer about pressures for best wear and efficiency in light truck tyres. I just bought a new set of Michelin XCDs but even they won't answer my emails. Neither will Toyota.

I have a 1986 YH51 HiAce VanWagon. I use it mainly for personal transport but it is also occasionally used for carrying heavy loads over short distances, like taking junk to the tip or bringing home stuff from the local landscaping supply house.

The old HiAce has a 2.0L carburetted 4-cyl, 5sp. I think it gets reasonably good fuel economy, 10.7 litres per 100 km or ~9.3 kilometers per litre. Sound OK to other carburetted HiAce owners?

The owners' manual sez the 185R14C (Light Truck) tyres should be run at front - 275kPa (39.8psi) and rear - 441kPa (63.9psi). The tyre sidewalls are stamped 65psi/450kPa.

If I can run the rear tyres at 64psi, can I run the front ones at 64psi, too? I'd think it would significantly improve the fuel economy. I've tried it for a couple of days and found it was like adding power steering! I didn't leave the fronts at that pressure, though. I thought there might be some wisdom to the Toyota engineers' recommendation for the lower front tyre pressure that I just don't know about.

Is it safe to run my front tyres also at 64psi?

Should I alter the pressures for running mainly unladen as opposed to when I have a load of rocks and potting soil?

Thanks!

Brian

Just follow what the owner's manual or what the sticker on the door jam says. Tire pressure should be taken at unladen weight and while cold.