tyre pressures with bull bar

[newby@54]

I own a MY16.5 Disco 4 fitted with an ARB steel bull bar. Its travelled about 29,000km still with the standard Goodyear Wranglers and I've just noticed that both front tyres are wearing on the outside of the tread. Apparently this is a classic sign of under inflation.

I've religiously maintained tyre pressures as per Land Rover specification i.e. 34 psi front and 37 psi rear when unloaded. But now I'm wondering with the weight of the bull bar that a higher psi is needed.

And then I got thinking about the LR specification for tyre pressures. I live in Maryborough Qld where the temperature is significantly warmer than that of Solihull UK. So when LR specify 34 psi front (and presumably this is a 'cold' temperature) what is the equivalent psi when the 'cold' ambient temperature is so much warmer than that of Solihull?

Has anyone any experience with tyre pressures with a bull bar vs the LR specified inflation pressures?

Thanks in advance

Nic

[BradC]

My local tyre guy did some measurements on my Kuhmo Solus and said they need to run up around 40 on my D3. Can't say how much of a difference it has made as they were pretty rooted when I bought the car but I haven't seen any extra significant wear. The fears have scalloped inner shoulders due to a bad alignment though.

[LGM]

Nic, I own a 2011 D4HSE and it was fitted with an ARB steel bull bar in 2012.
I have never changed the tyre pressures based upon the bull bars additional mass. In fact I never even considered it. I do adjust pressures for differing travel conditions or load but pretty much for normal driving stick with the placarded pressures. I have had Continental tyres, Cooper tyres, Pirelli Tyres and of recent times Hankook tyres (last two sets) and not had any issues or problems as you have described.

[4bee]

This could be worth a read.

Front Tires Wear on Outside Edge: Causes and Solutions - Tire Reviews, Buying Guide & Interesting Facts - Utires.com

[SeanC]

I thought under pressure wore both inside and outside edges. Over pressure wore the centre of the tyre while just inside or outside was a wheel alignment issue.

[scarry]

I thought under pressure wore both inside and outside edges. Over pressure wore the centre of the tyre while just inside or outside was a wheel alignment issue.

Correct.

Mine has a bar,and KO2's,i run 40 PSI on black top, no worries at all,and the last set did over 60K and wore evenly.

[4bee]

Mine has a bar,

Does it also have Refrigerated Keg Storage? It never ceases to amaze me what can be fitted into a LAND ROVER.

[newby@54]

Thanks for the replies. In my initial post I meant to say that the front tyres are wearing on both shoulders or edges - so under inflation. I've pumped them to 39 and will see how they go.

Nic

[Eric SDV6SE]

I own a MY16.5 Disco 4 fitted with an ARB steel bull bar..... So when LR specify 34 psi front (and presumably this is a 'cold' temperature)

34 and 37 seems too low to me, and yes, that would be cold pressures. Allowing for ~3psi increase when hot, 37 and 40 respectively still seems low for a car running 19" rims and weighing 2.7t. The wear you are describing is definitely from under inflation. Would have been a plush ride though.

I run my current set of LT 980's at 46psi cold on the highways and byways a nbd they are wearing evenly. The previous set of Cooper Zeons the same and got 70,000kms out of them with even wear all round.

I've also got an ARB steel deluxe bull bar, but honestly have never considered the additional weight of the bar in setting tyre pressures. I just set to what I'm comfortable with ride wise and ensures even wear.
Cheers

[DiscoJeffster]

Well to be fair Eric, it is what the factory specifies so it’s not too low normally. I’ve used factory 33/36 pressures on the road and not had abnormal tyre wear aside from when my rear toe was well out. I don’t have a 100kg roo bar so maybe I’d run a couple more if so, but probably not.

The OP might be suffering under inflation however I suspect more likely worn suspension components and alignment than pressure. It’s not uncommon to get a rubbish alignment on these from a generic shop which causes more harm than it solves