Defender 110 and 90 tyre pressure help

Defender 110 and 90 tyre pressure help

Author
Discussion

fitzmoresco

Original Poster:

150 posts

163 months

Saturday 18th April 2020
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Could some one let me know what pressures I should run for the tyres on both my Twisted 110 and 90s. Both are on BF Goodrich All Terrain 265/65 R18 all round.

Both are run around drives and not used for towing or loads. Just wife, kids and the dog

Thank you for helping

CSK1

1,680 posts

131 months

Saturday 18th April 2020
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I was running the recommended tyre pressures on my 2016 110 (same tyre size as yours) but found the ride very uncomfortable. I searched various forums, there are many differing views on the subject but many owners seem to find the recommended tyre pressures of 48 PSI/3.3 BAR at the rear too high.
So I asked my dealer for advice, he told me to stick to the recommended pressures, JLR Classic said the same.
Finally JE ENGINEERING/JE MOTORWORKS recommended running 2.4 BAR/35 PSI alround, it does improve the ride quality.
If loaded I would increase the rear to 2.7BAR/39 PSI.
For the 90, these must be different, why don't you drop JE an email?
I hope this helps!
Stay healthy, stay safe, stay home.

Edited by CSK1 on Saturday 18th April 23:47

fitzmoresco

Original Poster:

150 posts

163 months

Sunday 19th April 2020
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Thank you for this.

Along with my family we are being good citizens for everyone’s benefit!!!

100SRV

2,175 posts

249 months

Sunday 19th April 2020
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CSK1 said:
I was running the recommended tyre pressures on my 2016 110 (same tyre size as yours) but found the ride very uncomfortable. I searched various forums, there are many differing views on the subject but many owners seem to find the recommended tyre pressures of 48 PSI/3.3 BAR at the rear too high.
So I asked my dealer for advice, he told me to stick to the recommended pressures, JLR Classic said the same.
Finally JE ENGINEERING/JE MOTORWORKS recommended running 2.4 BAR/35 PSI alround, it does improve the ride quality.
Edited by CSK1 on Saturday 18th April 23:47
Does your 110 have the suspension without the Boge self-levelling strut? At 2016 I would guess so.
If that is the case it could be that being unladen, the higher spring rate, along with correct rear tyre pressures make the back of the vehicle too stiff.

My '96 110 has self-levelling suspension which also has (well-used) standard springs and rides nicely with 30 PSI front / 50 PSI rear.


C Lee Farquar

4,087 posts

223 months

Sunday 19th April 2020
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A 65 profile will be difficult to get a decent ride from and the standard ride will be be further affected by spring and damper changes that Twisted have made.

Is it the ride you're concerned about or just a concern to run at the 'right' pressure?



Jadatis

29 posts

196 months

Sunday 19th April 2020
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Needed tyrepressure is all about weight on seperate tyres and maximum speed, you wont go over for even a minute.

Or better , so not any part of tyre reaches a temperature, at wich the rubber hardens and beginning crackes are created.
Once this damage is done, mechanical forces, by the bending of the rubber by the deflecting and flexing back of every segment of tire , about 10 times a second when driving about 80kmph/50mph. destroys the tyre further, untill mayby only after 3 years that far, that tire blows or treath-separation. Then the moment that the beginning damage is done, is long forgotten.

So this overheating must never happen in the livetime of the tire.

Nowadays the car-and tyre-maker are responcible for preventing this tire-failure, so advices are kept verry high mostly. Also better milage at to high pressure.

But if you know what you are doing, with my help, you can determine a pressure, wich is safe , with max reserve and still acceptable comfort and gripp.
Probably this is for your loading and speed about 30 to 35 psi, but give weights and max speed used, and I will calculate.
Determining the weights, is the most tricky part in it all.

Edited by Jadatis on Sunday 19th April 11:43

fitzmoresco

Original Poster:

150 posts

163 months

Sunday 19th April 2020
quotequote all
Both been sat unused for last three weeks so wife wants to use for a food run. The rears on both looked a little sad and I didn’t have the chance to over pressurize them before the enforced lockdown. If we use one of them I will check the pressures but can’t recall the recommended PSi

CSK1

1,680 posts

131 months

Sunday 19th April 2020
quotequote all
100SRV said:
Does your 110 have the suspension without the Boge self-levelling strut? At 2016 I would guess so.
If that is the case it could be that being unladen, the higher spring rate, along with correct rear tyre pressures make the back of the vehicle too stiff.

My '96 110 has self-levelling suspension which also has (well-used) standard springs and rides nicely with 30 PSI front / 50 PSI rear.
Don't know about self-levelling suspension but 50 PSI seems incredibly high!

100SRV

2,175 posts

249 months

Sunday 19th April 2020
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CSK1 said:
Don't know about self-levelling suspension but 50 PSI seems incredibly high!
Standard pressure for Defender 110 is 28 front and 48 rear for all conditions with 235/85R16 tyres.

camel_landy

5,081 posts

190 months

Monday 20th April 2020
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100SRV said:
CSK1 said:
Don't know about self-levelling suspension but 50 PSI seems incredibly high!
Standard pressure for Defender 110 is 28 front and 48 rear for all conditions with 235/85R16 tyres.
...and IIRC it can even go up to 60psi for the rears (that would be for a fully laden 110, HD rear & 7.50 R16).

M

CSK1

1,680 posts

131 months

Monday 20th April 2020
quotequote all
100SRV said:
CSK1 said:
Don't know about self-levelling suspension but 50 PSI seems incredibly high!
Standard pressure for Defender 110 is 28 front and 48 rear for all conditions with 235/85R16 tyres.
You haven't read my reply to the OP above. I know the recommended tyre pressures, they're on my placard and handbook, I was saying that 48 PSI at the rear carrying no load is way too high. There's no justification for this massive pressure difference front to rear (carrying no load), 48 is unnecessary high and makes for a bouncy ride, it takes all of your fillings out running these pressures!
I've been playing around with pressures a lot, running 35 alround suits me, I trust JE MOTORWORKS' advice, you can't question their experience working on Defenders.
If you're OK running even higher pressures than the already high recommended ones, why not, it's a free world!

C Lee Farquar

4,087 posts

223 months

Monday 20th April 2020
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And obviously there are no standard pressures for 18" tyres on a Defender.

100SRV

2,175 posts

249 months

Monday 20th April 2020
quotequote all
C Lee Farquar said:
And obviously there are no standard pressures for 18" tyres on a Defender.
What he said ^

If JE Engineering have given you advice that is great - might also be worth referring to the tyre manufacturer giving them the mass details for each axle (from weighbridge) to be sure. Michelin were very helpful with this on our modified vehicles (fire tenders).

CSK1

1,680 posts

131 months

Monday 20th April 2020
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Indeed. Apologies I didn't take much notice of the OP's tyre size and assumed this to be standard tyre size for late model Defenders.
Mine are 235-85-16 so pressures may defer for the OP's larger tyre size.
Why don't you give Twisted a call?

Likeomg

164 posts

105 months

Tuesday 28th April 2020
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I've ran 35 on my 285/65/18's from twisted for the last 4-5 years

started on the BFG's but moved to cooper Zeon LTZ in 285/60/r18 and still running 35 (although so much better on the road) and for the off road i do no difference.

Rides great, comfort springs, uprated arb, fox adjustable dampers.

100SRV

2,175 posts

249 months

Tuesday 28th April 2020
quotequote all
Likeomg said:
I've ran 35 on my 285/65/18's from twisted for the last 4-5 years

started on the BFG's but moved to cooper Zeon LTZ in 285/60/r18 and still running 35 (although so much better on the road) and for the off road i do no difference.

Rides great, comfort springs, uprated arb, fox adjustable dampers.
The key there is the dampers, standard or pattern parts are valved for vehicles with standard wheel/tyre combination. Fox (are they Prolinx, OP?) are significantly better than standard as it is but can be revalved to suit the driver and wheel/tyre/spring combination.