Correct T4 Tyre Pressures?

[Gold Coaster]

I have a 1996 SWB 2.0 petrol T4 with a part camper conversion ..... so not much extra weight - rear fold down seat, small cabinet for fridge and aux battery.

The placard on the driver's side pillar states that my 205/65R15C tyres should be 43 PSI for front and 48 PSI for the rear (regardless of load) which I have been abiding by.

I noticed that both front tyres are wearing prematurely on their outside edge so I went back to see the tyre guys from where they were purchased just over 12 month ago (had a wheel alignment then also).

He seemed to think that the problem was that I have been driving with them with too low a pressure and recommended that I should run 50 PSI all round with this size tyre.

Does this sound reasonable? What pressure do others run with this size tyre?

[Seano]

Sounds like a poor wheel alignment to me...

I run a TDi engine in the DOKA and run 48 f and 46 back (340/320) and it wears nice and flat

[brad]

Premature wear on the outside edge of both wheels would denote a lack of negative camber. If there's a bit more wear on the LH side then maybe a bit much toe-in as well.

If the wear is on both edges of the front tyre then it could still be alignment (excessive -ve camber + excessive toe-in or not enough -ve camber & not enough toe-in.

Or it could be lack of air pressure. I find that as suspension bushes, springs & dampers age you have to add a bit more air to the tyres to compensate /mask the extra movement in teh components.

I generally run the front tyres (on any car) a bit higher than the factory recommendation. 48/50 all round is worth a try but I'd also have a good look at the alignment as well.

Try Accurate Suspension or ask Jmac at Alba European who he uses.

[jets]

I run mine at 350kpa front & 320 rear as recommended. I have just fitted a full set of new tyres [syncro] & they are wearing nicely with fairly square corners at the front. I have never needed an alignment, the previous tyres also showed no sign of abnormal wear but then because of the syncro trans. I would watch wear & rotate accordingly.
I agree with others on here, probably needs alignment.

[brad]

I run mine at 350kpa front & 320 rear as recommended. .

that's 51psi front / 47psi rear.

OP says that his decal says 43psi (300kpa) front & 48psi (330kpa) rear.

Either one of you has misread the label or VW have made a running change to the specs.

350F/320R sounds better than the OPs specs.

[Gold Coaster]

Got me thinking so I rechecked and the info that I posted was correct.



Did a bit a of googling on this and in the UK many appear to run a higher pressure in the front tyres than in the rear, as jets does, but there is no real consensus to what these pressures should be?

[Seano]

Diesel engines are heavier than petrol engines...so I suspect that petrol vans like Gold Coaster's runs lighter front pressures than Jets and I have to.

[brad]

Diesel engines are heavier than petrol engines...so I suspect that petrol vans like Gold Coaster's runs lighter front pressures than Jets and I have to.

there'd only be 100kg between a petrol & a diesel engine. That's about 2-4psi extra needed which doesn't explain the extra 4psi on top of that.

OP: You'll find people have arrived at a pressure through trial & error and finding a happy medium between ride, tyre wear & handling.

A really rough way of working out if the tyre pressures are right (this doesn't always work) is to check the pressures cold (say 43psi) then check them after driving under (your) normal conditions for 30 minutes. If the pressure increase by more than 10% (say 48psi) then the cold pressure is insufficient. Add 10% when cold & repeat until the pressure rises only about 2psi.

It's a lot of faffing about when i can almost guarantee that 50 psi up front will solve a lot of your issues.

[Gold Coaster]

A really rough way of working out if the tyre pressures are right (this doesn't always work) is to check the pressures cold (say 43psi) then check them after driving under (your) normal conditions for 30 minutes. If the pressure increase by more than 10% (say 48psi) then the cold pressure is insufficient. Add 10% when cold & repeat until the pressure rises only about 2psi.

Thanks Brad, I'll give that a go ...... got nothing to lose! I'm the only one who drives the van and I reckon that I drive pretty carefully so I'm thinking that the last wheel alignment should still be ok.

[jets]

there'd only be 100kg between a petrol & a diesel engine. That's about 2-4psi extra needed which doesn't explain the extra 4psi on top of that.

Seano & I have Syncro versions that add around another 100kg. We also have later vans ['01] so maybe VW decided to increase pressures
over the years.

[brad]

They do stuff it up & revise it.

IIRC, initial factory recomendations for Holden Gemini was about 24-26psi. It was fine on the rear but the fronts got horrible inner/outer edge wear. 34psi and some wheel alignment tweaking transformed them.