20" Propellers different tyre sizes than factory ???

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Robo
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20" Propellers different tyre sizes than factory ???

Post by Robo » Sun Mar 21, 2021 11:02 am

Just a quick one wonder if anyone on here is running a different size on there 20" Propellers than factory ???

Front 235/35 R20 92Y

Rear 265/30 R20 94Y

Reason : Roads around here are shocking was considering a slightly bigger sidewall ratio to smooth out the ride and possibly reduce road noise.

chrisjp
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Re: 20" Propellers different tyre sizes than factory ???

Post by chrisjp » Sun Mar 21, 2021 11:38 am

Yes, I reckon you need at least 45 aspect ratio to deal with the appalling state of the UK's roads.
On one of my local roads we've had a huge pot hole around a drain cover for several months. The local authority has now "dealt" with it by putting up traffic lights and one lane working - but there has been no sign of any repair work for about a month so far.
Chris Phillips. Jaguar XE HSE 250PS Petrol MY20. Portofino Blue, Light Oyster, privacy glass, heated steering wheel, Meridian 825w, space saver spare wheel, folding rear seat, black pack, 16-way driver seat

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PhilB
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Re: 20" Propellers different tyre sizes than factory ???

Post by PhilB » Sun Mar 21, 2021 11:59 am

It may be better to downsize to a 19" wheel as having a deeper aspect ratio than standard on a 20" will throw your speedo out and you will have to notify your insurance.
2019 Evoque P300 HSE - now gone awaiting the "Beast from the West" est end of 2021
2017 XE S 380, Carpathian grey.
2015 XE S 340, British Racing Green.

Robo
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Re: 20" Propellers different tyre sizes than factory ???

Post by Robo » Sun Mar 21, 2021 4:17 pm

PhilB wrote:
Sun Mar 21, 2021 11:59 am
It may be better to downsize to a 19" wheel as having a deeper aspect ratio than standard on a 20" will throw your speedo out and you will have to notify your insurance.
Knocks speedo out by around 3% to the safe side, so 70mph on speedo is actually 67.9mph Road speed

My insurance never bothered when I fitted the winter tyres and phoned to tell them

There is certainly a debate to be had about cheap budget tyres even the right size being put on vehicle that are lesser than manufacturer spec. As well as winter tyres being used in the summer. That's one discussion for another thread...

Tempest XE S
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Re: 20" Propellers different tyre sizes than factory ???

Post by Tempest XE S » Wed Apr 21, 2021 9:20 am

Wondered the same thing myself.

My rears are particularly susceptible to potholes it seems (2 cracked rear rims in 18 months). I've read someone has used the 35mm profile all round and has had no issues but I'm not sure I want to do it if it's going to cause insurance problems.

It's either thicker profiles or leave them be and accept the consequences imo, changing the rims to a smaller size isn't an option as I just love how they look on the car.

Need two new tyres for the rear relatively soon as well.

Decisions, decisions.
Jaguar XE-S / 3.0L Supercharged V6 335 BHP / Tempest Grey / 20" Propeller alloys / Black Pack

To come: Ceramic paint coating, chip re-map to 404 BHP, spacers, badge black out

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147daytona
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Re: 20" Propellers different tyre sizes than factory ???

Post by 147daytona » Wed Apr 21, 2021 12:59 pm

The difference in tyre height from a 265/30 and a 265/35 is only about 13mm or 1/2", not enough to really make a noticeable difference if you hit a pothole hard!

I wonder why the rears are causing an issue and not the fronts?
MY20 Carpathian Grey 300 R-Dynamic HSE AWD + loads of extras!
Previous, MY17 Italian Racing Red 240 R-Sport

chrisjp
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Re: 20" Propellers different tyre sizes than factory ???

Post by chrisjp » Wed Apr 21, 2021 4:23 pm

Yes, I think you've got to go to 45 or even higher aspect ratio to give some protection of the wheels against pothole damage. An additional benefit of doing so is a quieter ride, but I agree smaller wheels/bigger tyres don't look so good - or is that just a fashion that we've all become accustomed to? My "other" car is a Cavalier V6 with 60 aspect ratio tyres and 15" wheels, and it is MUCH quieter on the road than my XE, despite its cruder suspension.
Chris Phillips. Jaguar XE HSE 250PS Petrol MY20. Portofino Blue, Light Oyster, privacy glass, heated steering wheel, Meridian 825w, space saver spare wheel, folding rear seat, black pack, 16-way driver seat

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