Discovery 2017

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  • BruceT
    Member Since: 17 Sep 2019
    Location: South Africa
    Posts: 71
    South Africa 
    2017 Discovery TDV6 HSE Fuji White

    Changing to 275 55 20

    Hi All,

    I am considering changing to 275 55 R20 from the standard 255 55 R20 tyres.

    Are there any negatives to doing so?

    Would you recommend I change the spare wheel also? The spare wheel will only be used if a tyre is damaged? The spare is a 255 55 R20.

    Thank you
    22nd Nov 2019 9:37 am
  • Slug
    Member Since: 19 Jan 2019
    Location: East Midlands
    Posts: 86
    United Kingdom 
    2020 Discovery SDV6 HSE Silicon Silver

    https://disco5.co.uk/forum/post21790.html#21790
    I asked a similar question a while ago.
    Thumbs Up
    22nd Nov 2019 11:33 am
  • BruceT
    Member Since: 17 Sep 2019
    Location: South Africa
    Posts: 71
    South Africa 
    2017 Discovery TDV6 HSE Fuji White

    Thank you Slug. Sorry about that. I will ask my questions there

    moderators please feel free to delete this thread.

    Thank you
    22nd Nov 2019 12:00 pm
  • harrythespider
    Member Since: 19 Jul 2018
    Location: cumbria
    Posts: 427
    United Kingdom 
    2017 Discovery TDV6 HSE Aintree Green

    Bruce, I changed the spare to 275, (a), to match exactly the rolling radius and (b), if in the event of a puncture or damage the spare would match the rest, (c), I got a good deal on 5 tyres., (d) because all 5 match, I can rotate them so I don't end up with 4 worn and 1 full tread.
    3.0 HSE. climate HUD active diff. elec towbar. FBH and timed climate.Capability plus pack.split TV. surround sound. Intelligent seating. adaptive lights, wade sensing. 360 cameras.pro pack.cooler.advanced tow, auto park,activity key+ more!!!!
    22nd Nov 2019 1:17 pm
  • BruceT
    Member Since: 17 Sep 2019
    Location: South Africa
    Posts: 71
    South Africa 
    2017 Discovery TDV6 HSE Fuji White

    thank you harrythespider.
    22nd Nov 2019 2:07 pm
  • Numb Thumbs
    Member Since: 05 Nov 2019
    Location: Melbourne
    Posts: 17
    Australia 
    2019 Discovery SDV6 SE Fuji White

    Definitely go five the same. You don't want to have to drive with one wheel a 31" and one a 32".

    Cheers
    Numb Thumbs Wink
    23rd Nov 2019 4:41 am
  • Craigp
    Member Since: 09 Nov 2016
    Location: Hull
    Posts: 690
    England 

    Forgive my ignorance but isn't it just the width of the tyre thats different?
    23rd Nov 2019 11:30 am
  • JonM
    Member Since: 30 Jun 2016
    Location: North Yorkshire
    Posts: 666
    United Kingdom 
    2022 Discovery SDV6 HSE Carpathian Grey

    The width is different but the 2nd number e.g 255/55R20 is the profile expressed as a percentage of the width.

    So if the width is increased by 20mm and the profile is still 55 then the tyre has 11mm more sidewall which is 22mm more diameter overall.
    MY2026 D5 Metropolitan D350 - on order......
    MY2022 D5 HSE D300 - current, MY2019 D5 HSE SD6 - sold
    23rd Nov 2019 6:54 pm
  • Craigp
    Member Since: 09 Nov 2016
    Location: Hull
    Posts: 690
    England 

    Thanks Jon. I wasn't aware the 2nd number was a percentage thought it was a actual measurement hence my confusion Thumbs Up
    23rd Nov 2019 6:58 pm
  • Numb Thumbs
    Member Since: 05 Nov 2019
    Location: Melbourne
    Posts: 17
    Australia 
    2019 Discovery SDV6 SE Fuji White

    I use the web site Tire Calculator:

    https://tire-calc.com/

    It is very handy for comparing tyre sizes. This is a comparison on 255/55R20 and 275/55R20. There is more information, but the cropped image is the gist of it:



    Cheers
    Numb Thumbs Wink
    23rd Nov 2019 10:40 pm
  • Labbix
    Member Since: 05 Mar 2018
    Location: Tanzania
    Posts: 955
     

    Numb Thumbs, thanks for the website, very clear and useful!
    24th Nov 2019 8:01 am
  • BruceT
    Member Since: 17 Sep 2019
    Location: South Africa
    Posts: 71
    South Africa 
    2017 Discovery TDV6 HSE Fuji White

    Thank you.

    Im also stuck on whether i should fit 255 55 r20's or 275 55 r20's.

    Main disadvantage of the 275's is I will need to purchase 6. Advantage is the slightly higher profile.
    25th Nov 2019 7:19 am
  • DieselRanger
    Member Since: 12 Oct 2017
    Location: God's Country, Colorado
    Posts: 782
    United States 
    2017 Discovery Td6 HSE Silicon Silver

    Personally, having followed Kingsley Holgate's expeditions with their D5s, if I were you I'd go all in on some Compomotive 18" wheels and 265/65-18 if you plan on the kinds of things they do down there. That's a 31.6" tire and will fit without a lift or rubbing, slightly smaller outside diameter than 275/55-20, and LOTS more sidewall. Wrangler DuraTracs are available in that size in the US, not sure about ZA.

    265/70-18 is just over 32" and *should* fit but might rub in access height. General Grabber X3's are available in that size here.

    33" tires will supposedly fit with lift rods but some claim increased duty cycling on the air suspension and thus higher chance of early failure.

    Short of that, my 275/55-20's have served very well in the Rocky Mountains. Just not a whole lot of room to air down without risking rim damage, but so far there's nothing the D5 hasn't been able to surmount.
    25th Nov 2019 11:56 pm
  • BruceT
    Member Since: 17 Sep 2019
    Location: South Africa
    Posts: 71
    South Africa 
    2017 Discovery TDV6 HSE Fuji White

    Thank you. I have contacted Compomotive already. (had them on my D4)

    Unfortunately they wont fit onto my D5. Something to do with the rear brakes. I have a feeling kingsley's vehicles changed their brakes to fit the compomotives.

    This is what they said:

    "Sorry to say that we do not a wheel to suit your version of the Discovery… all due to the size of the rear brakes fitted.

    I think that we are not alone…"
    26th Nov 2019 7:39 am
  • Labbix
    Member Since: 05 Mar 2018
    Location: Tanzania
    Posts: 955
     

    BruceT, here you go regarding Kingsleys mods:

    Discoverys

    We fitted the 2018 Discoverys with a Frontrunner roofrack with mud ladders, a spade, a spare wheel bracket, a front LED light bar, and two Jerry cans for spare diesel.

    At the rear of the vehicle, we mounted a wireless Warn winch system and a removable tow bar.

    Inside the vehicle, we have a luggage cage behind the rear seats, and a ‘floating’ dual-battery system with a mounted ARB air compressor.

    The vehicle is fitted with Melvill & Moon seat covers; and, for communication, each vehicle has a VHF mobile radio system.

    To fit 18-inch rims, we modified the brake callipers; and we are running Cooper 275/65 R18 ST Maxx tyres.

    For suspension, we increased the ride height of the vehicle slightly, to prevent overuse of the vehicle’s air compressor in off-road conditions.

    From the SA4x4 app Wink
    28th Nov 2019 9:16 pm
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