half load and full load tire pressures

[huffmuds9320]

On my dad's Toyota Camry, it lists two sets of tire pressures. One is for "up to 4 passengers" 26psi all tires. And the other is "up to the load of the vehicle" 29psi all tires. On the other hand the VW Jetta list for half load 26psi all tires and for full load 30psi front 40psi rear. I think on the newer VWs they only put the full load pressures. So would it be a good idea to use the full pressures. I find that 26psi in all tires would be a bit low considering the 44psi max tires. Also is it true that newer cars now only list one set of pressures(full load) and don't put half load anymore?

Currently I run 30psi on the Camry tires since it gets loaded often. On the VW I run 26psi since that car rarely gets loaded.

 

[Master ACiD]

i think most cars only give a full load psi. however it makes logical sence that the front tyres should require more air then the rears. afterall that is where the engine and transmission are, and theres awalys atleast 1 person sitting in the front of the car when its moving.

 

[spingdaddy]

If he drives solo most of the time, I would run the half load ratings. The wife's Beetle not only has half and full load PSI settings, but also for over or under 100 MPH, leaving four possible configurations. Remember, recommended PSI from the vehicle manufacturer is a compromise between traction, handling, MPG, noise, treadwear, etc.

 

[eljefino]

I pay attention to the "offset" in pressure between front and rear, as I figure the suspension engineers took tire pressure into consideration. Only on a car that I only drive, and drive every day, do I vary from that consideration to see how much it affects over/understeer, etc. IOW, if I'm going to add a few pounds, I do it to all four corners equally.

I've only seen the "lightly loaded" recommendation on a dodge spirit that ran 32 instead of 35.

One manual (I forget which car) said to go an extra 4 psi over if driving at sustained speeds over 75 mph.

 

[CapriRacer]

Personally, I think having 2 pressures listed on the placard leads to confusion.

Plus if one were to use the lower of the 2 pressures (because the vehicle is empty most of the time), then the pressure ought to be bumped up when the conditions change - and I don't think most people remember to do that.

So my recommendation is to use the highest pressure listed. Most of the tire properties that people want are better if the pressure is higher (fuel economy, steering response, tire wear, tire durability, etc.) Probably the only desirable property that gets worse with higher pressure is ride harshness.

 

[surfstar]

quote:

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Originally posted by CapriRacer:
So my recommendation is to use the highest pressure listed. Most of the tire properties that people want are better if the pressure is higher (fuel economy, steering response, tire wear, tire durability, etc.) Probably the only desirable property that gets worse with higher pressure is ride harshness.

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I agree 100%. Much better fuel economy can be seen with a bump in tire pressure (26-30 up to 35psi) and the handling is noticeably better also. Bumps are a little sharper, but that's the only downside.