Other tyre pressures

[Martin1621]

Hi all

I hope someone can help I have 2006 2.4 converted to a camper.

my wheels are : front 225  40 z r 19 93y.            And rea r are :  245  40 z r 19 98y with low profile tyres to suit

My gross weight is about 10kg it short of maximum what tyre pressures should I be using and are they the same  back and front. Thanks for reading this.

Martin

[pcous]

Hi Martin1621,

 

I recall seeing a post on this forum stating 38-40psi generally, and our campervan converter suggested 38pi both front & rear. So, you could ask whoever did the campervan conversion (perhaps the simplest solution). Alternatively, it might involve quite a bit of sleuthing & emailing....

 

These were the weight figures we were given from the Japanese import certificate (Gen 1 2005-07):

Weight	Total	Front	Rear
	(kgs)
Car: Net	1870	1070	800
Car: Revenue (i.e. GVW)	2255

 

So there's a difference of 385kg between unladen and laden weight (which doesn't seem a lot for a 7/8 seater...) for the base Alphard, but there was no breakdown in the figures for front and rear separately when laden. When converted, there's the added unladen weight from permanent campervan furniture, but not 5-6 people in the back when laden. After messing about on a weighbridge several times, putting the whole vehicle on then the rear only (and subtracting the difference), we worked out the unladen and laden weights for each axle. Divide the axle weight by 2 to get a load for each tyre...

 

Tyres are weight (and speed) rated, so your 93Y on the front can each carry 650kg maximum (1300kg for the front axle overall) and 98Y on the rear can take a 750kg max load each (1500kg for the rear axle). So far so good, but the recommended Alphard tyre pressures in the manual (34psi or 2.3kg/cm2) are for the base vehicle rather than as a campervan and ultimately it depends on your max weight (front & rear), also the tyre type/manufacturer .

 

For our campervan , Continental, Falken, Kumho and Nokian responded to e-mail enquiries, but to get them to offer figures we needed to point out that the conversion meant that standard Toyota figures didn't apply, and choose a specific tyre first to ask them about, rather than making a general enquiry. In the end we went with Falken  front & Nokian van tyres rear, which the manufacturers said should be 34 & 41psi respectively, but this was based upon our weighbridge figures which showed that, when laden, the extra weight primarily loaded on the rear axle (gear & bikes on towbar etc...) and made no substantial difference to the front end. Of course this is just an example to show that tyre pressures may need to be different front and rear - your situation may be different....

 

Regards,

pcous

 

 

 

 

 

[Rojie]

15 hours ago, pcous said:

Hi Martin1621,

 

I recall seeing a post on this forum stating 38-40psi generally, and our campervan converter suggested 38pi both front & rear. So, you could ask whoever did the campervan conversion (perhaps the simplest solution). Alternatively, it might involve quite a bit of sleuthing & emailing....

 

These were the weight figures we were given from the Japanese import certificate (Gen 1 2005-07):

Weight	Total	Front	Rear
	(kgs)
Car: Net	1870	1070	800
Car: Revenue (i.e. GVW)	2255

 

So there's a difference of 385kg between unladen and laden weight (which doesn't seem a lot for a 7/8 seater...) for the base Alphard, but there was no breakdown in the figures for front and rear separately when laden. When converted, there's the added unladen weight from permanent campervan furniture, but not 5-6 people in the back when laden. After messing about on a weighbridge several times, putting the whole vehicle on then the rear only (and subtracting the difference), we worked out the unladen and laden weights for each axle. Divide the axle weight by 2 to get a load for each tyre...

 

Tyres are weight (and speed) rated, so your 93Y on the front can each carry 650kg maximum (1300kg for the front axle overall) and 98Y on the rear can take a 750kg max load each (1500kg for the rear axle). So far so good, but the recommended Alphard tyre pressures in the manual (34psi or 2.3kg/cm2) are for the base vehicle rather than as a campervan and ultimately it depends on your max weight (front & rear), also the tyre type/manufacturer .

 

For our campervan , Continental, Falken, Kumho and Nokian responded to e-mail enquiries, but to get them to offer figures we needed to point out that the conversion meant that standard Toyota figures didn't apply, and choose a specific tyre first to ask them about, rather than making a general enquiry. In the end we went with Falken  front & Nokian van tyres rear, which the manufacturers said should be 34 & 41psi respectively, but this was based upon our weighbridge figures which showed that, when laden, the extra weight primarily loaded on the rear axle (gear & bikes on towbar etc...) and made no substantial difference to the front end. Of course this is just an example to show that tyre pressures may need to be different front and rear - your situation may be different....

 

Regards,

pcous

 

 

 

 

 

 

Just one other small point to consider.

 

The front to rear weight distribution is different depending on whether you have side or rear conversion !