Couple of questions about my 'new' NH

[OlDeezel]

Hi Folks

Recently acquired a very nice 2.5TD NH, but a couple of questions...

Tyre pressure: From scanning the forum I know this is an old chestnut, but I am running on new all-terrain Silverstone 15-10.5-31s (part of the purchase deal) and when delivered the tyre fitters had them at 45psi. I lowered that to 32psi (highway use). Recently I had the wheels balanced/rotated/aligned NOT by the original fitters and once again the car was returned with tyres inflated to 45psi. I have let a lot of air out again, but am wondering who is right??

Diff ratio On the above 31" tyres 3200rpm in OD (manual box) = 100kph. Mechanic suspects non-standard diff ratios??

Andy

[Jaydee]

I have let a lot of air out again, but am wondering who is right??

Diff ratio On the above 31" tyres 3200rpm in OD (manual box) = 100kph. Mechanic suspects non-standard diff ratios??

I reckon your closer at 32psi..... 45psi is very hard but some people like them rock hard.... consequence is they become prone to sharp bitumen stone punctures because there's no give. 32psi allows some give.

Mine of the same size run at 28psi most of the time regardless of terrain except if I'm cutting up the beach or track then they're dropped to 16psi.

What's the tyre placard show ?

[MITSIR]

This is why I pump mine half way from 32- 45psi. Normally I have them on 38psi cold pressure which will then rise about 2-3 psi on hot Pressure.

Hope this helps

[dolphin]

apparently the stock tyre fitted to these models were Yokohamas and these were set at 45 psi. remember these are not real light vehicles so i wouldn,t go under 40 psi for around town and highway use.

[6G74]

Where do you get 45 from? Feel how hot your tires get after some driving - at a minimum, you can safely run mid - low 20's without anything in the back, that is if you want your car to feel like a boat, like wise, if you want it to feel like there is very little suspension at all, do as dolphin surgests

[dolphin]

under inflation of tyres will cause wear to the outer tread plus makes your vehicle feel like it wants to roll, over inflation will cause tyre wear to the middle tread area but your vehicle will feel nice and tight on the road. do not think by lowering tyre pressure will supply better suspension as this is why we have items such as springs and shockies. the only time to lower these pressures is when you go off the road to a sandy / muddy surfaces where more width of grip is required. i had my NH for 9 years with the original Yokohamas set at 44 psi and these wore very well , the only time i dropped tyre pressure was when it was time to hit the soft sand [ 20 psi ], when the vehicle hit hard sand with this low pressure it felt like i had a flat tyre. wobble wobble slip slip.

[Jaydee]

I dunno about handling like a boat... my sail boat turns in it's own length and goes where I steer it... probably need a snorkel to try the Paj as a boat to test the annalogy

[OlDeezel]

I reckon your closer at 32psi..... 45psi is very hard but some people like them rock hard.... consequence is they become prone to sharp bitumen stone punctures because there's no give. 32psi allows some give.

Mine of the same size run at 28psi most of the time regardless of terrain except if I'm cutting up the beach or track then they're dropped to 16psi.

What's the tyre placard show ?

Placard shows 26(F) 29(R) Lightly Loaded (Up To 3 passengers)

I left them at 45psi the second time the 'professionals' put them there, but was on the Woods Point road to Matlock last weekend and she was a tad lively on the corrugations. I let then down to 32 all round on the spot and she was much more stable. Your suggestion of 28 might have been better...

45 feels too high even on the highway - very light steering and the tyre is absolutely 'round'. At 32 they look 'right' - very slight bulge at the bottom.

Thanks for all the replies - new to this and absolutely loving it


... at the top of Matlock Hill...

Andy

[martin7]

best on this subject is your tyre pressures should go up by 4psi from cold to hot. other way to check is on a flat drive way place some talc powder on the drive and drive over it and check what sort of pattern you get.
with my NJ i run them at 32psi cold and after a 160km run to work they are at 36psi when i park up
cheers murray