My Scout has got the 17" alloy wheels.

Sometimes I use it alone but mostly with either 1, 2 or 3 adult passengers with/without our small white dog and can also have a boot-full of shopping or metal-detecting kit.

As with all cars there are 2 recommended sets of tyre pressures - light-load or heavy-load.

I'm sure that nobody goes out before every journey and adjusts tyre pressures specifically for every payload so what pressures should I set my tyres to for "general purpose" use?

 

 

I have mine set to 2.5 bar (37 psi) for both front and rear on 225/50/17.  It's probably just me in the car more often than loaded with family and dog but I don't see that as an issue.

 

When we go camping with the roof box and trailer I will increase the rears to 3.1 bar as per the guide on fuel filler but drop back to 2.5 when we get back.

@ScoutCJB recommendations are sensible for most situations but you do have to consider the variables involved. Four adults from my family would weigh less than 240kg whereas as my friend's family would weigh 200kg more, in which case 37psi might even be marginal. I don't adjust my pressures if we pick our friends up for a short local trip (I'm not that anal).

 

There are couple of areas where correct tyre pressures for weight are critical:

1. A longer high speed journey where rapid flexing of sidewalls of under-inflated tyres (for weight carried) can cause overheating of tyres.

2. Heavy braking throws the majority of the weight of the vehicle and contents (multiplied by rate of deceleration) onto the front tyres, double/triples(?) the static load on the front tyres. This extra load causes the outer walls to deform outwards and the distortion lifts the centre of the tread  off the road and this obviously severely affects braking performance. Correct higher pressures minimise braking distortion.

In the days before ABS, accident investigators often came across the signs of locked braking where the outer edges of the tyres only left two sets of parallel skid marks.

 

There are other tyre type factors, but that is probably overthinking it.

 

I have seen others on this site recommending running at lower pressures for ride comfort, and that may be true, but I cannot see the logic of compromising safety to that extent.

 

I had to smile at the OP's inclusion of the dog's colouration into the calculation. Obviously white is a 'lighter' colour  

 

I always set mine in between the recommended empty & loaded values shown in the fuel flap.

I have never had a problem running like this & tyre wear of 3 set of tyres has been even & lasted a good distance.

8 hours ago, Gerrycan said:

@ScoutCJB recommendations are sensible for most situations but you do have to consider the variables involved. Four adults from my family would weigh less than 240kg whereas as my friend's family would weigh 200kg more, in which case 37psi might even be marginal. I don't adjust my pressures if we pick our friends up for a short local trip (I'm not that anal).

 

But you think about it for the whole journey with them right?  

3 hours ago, Gabbo said:

 

But you think about it for the whole journey with them right?  

Yes I do! Dammit!

Proves that I am anal after all, just lazy.

As above, my Scout is set to the 'light-load' pressures 95% of the time (2x adults 2x young children, empty boot).

 

When we go abroad on holiday as a family with a full boot and roof box I run at the 'high load' pressures as per the recommendation inside the fuel filler flap.

 

It has to be said though, on the drive back from the petrol station before loading the car and the ride is significantly harder, enough to be unpleasant, so enough of an incentive to reset the pressures when we get back from holiday!

20 hours ago, ScoutCJB said:

I have mine set to 2.5 bar (37 psi) for both front and rear on 225/50/17.  It's probably just me in the car more often than loaded with family and dog but I don't see that as an issue.

 

When we go camping with the roof box and trailer I will increase the rears to 3.1 bar as per the guide on fuel filler but drop back to 2.5 when we get back.

Decided to do the same as you but went for 38PSI on all four tyres.

Once I've fitted the roof box and fully-loaded for our trip to Wales in June I'll increase the rear to recommended fully-laden 3.1 Bar too.

 

On 21/03/2018 at 00:04, Gerrycan said:

@ScoutCJB recommendations are sensible for most situations but you do have to consider the variables involved. Four adults from my family would weigh less than 240kg whereas as my friend's family would weigh 200kg more, in which case 37psi might even be marginal. I don't adjust my pressures if we pick our friends up for a short local trip (I'm not that anal)...........

 

I had to smile at the OP's inclusion of the dog's colouration into the calculation. Obviously white is a 'lighter' colour  

 

 

Agreed, every journeys different.  I'd say I'm not that anal as well but then I've got a transparent 5 litre container marked at different levels that I use for mixing the screen wash concentrate 

 

Whilst our brown dog won't tip the balance I suspect the camping supplies (lager, crisps and burgers) might!

Edited 22 March, 20188 yr by ScoutCJB

Interesting reading this how most people are using the bar figures. I'm still a little old school in that sense and I convert the figures to psi as I think it is slightly more accurate.  I usually drive on my own so use the unladen figures 2.2bar or 32psi. 

After reading these posts and in particular the post from Gerrycan i will now adjust my pressures up a tad and try them on 34psi. I'll always use the guide as exactly that - a guide. Then I'll see how they look and feel and how the car handles. We all drive different styles so i think its important to have the car set up for the driver and then adjust accordingly for the load and temperature. My white brown and purple dog doesn't seem to affect the weight too much!!! I do check the car almost every week and can be a bit anal with tyres. I've done about 12k now and tyres are still on 5mm so not too bad so far. My winters (dunlop 4d) seemed to perform better at 33psi.

Its good to get other peoples views on this subject though and as usual Briskoda is a great way to get info. Have any of you briiliant Scout owners done many tweeks with vcds yet? I did a few basic ones such as speed signs and needle seeep, just wondered what else there was?

I too still use PSI.

Mind you I still measure in feet and inches and harp back to when money was worth something (in pounds, shillings and pence)!

Lol