I'm in need of some new rubber.
I'm running 255.50.20 at the moment but there are some 255.55.20 on fleebay at a very reasonable cost.
L405 runs on 255.55.20 so have anyone put these on their L322 and what are they like

Thanks in advance

Jay  2020 Porsche Panamera Turbo Hybrid (V FAST)
2017 Range Rover Autobiography 5.0 V8
2018 JCW Mini Cooper
2018 Skoda VRS

anyone  2020 Porsche Panamera Turbo Hybrid (V FAST)
2017 Range Rover Autobiography 5.0 V8
2018 JCW Mini Cooper
2018 Skoda VRS

craig reckons they ride more smoothly, thread on here somewhere... ... - .- -.




Y. O. L. O.
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http://www.fullfatrr.com/forum/topic26461.html ... - .- -.




Y. O. L. O.
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What happened to the 22's Jay?

I have had them on for over a year no problem.

I suspect my odometer under reads by about 10%, may have been the same with the last tyres, when comparing distances to planner distances but reckon speedo is still accurate.

Ian

this chart shows the speedo difference between the 50 and 55 profile ratio,



speedo's are meant to under read so the 55 ratio will bring it up to more or less a 'true' speed. ... - .- -.




Y. O. L. O.
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Craig

Winter is coming and i need to have M&S tyres on where i live.

 2020 Porsche Panamera Turbo Hybrid (V FAST)
2017 Range Rover Autobiography 5.0 V8
2018 JCW Mini Cooper
2018 Skoda VRS

255/55-20 is great. It gives a smoother ride - does not rub at all  Range Rover TdV8 Autobiography MY2010
Defender 110stw Td5 MY2006

^^^ Stan - that doesn't make any sense at all.

As your tables correctly show the 55 has a larger diamter / circumference than the 50 and will therefore do less rpm for any given speed. The speedo takes a measurement of wheel rpm and calculates the speed from it via a fixed formula.

Therefore, if your speedo is accurate and shows 70mph when you are doing 70mph then with the 55s fitted you'd be doing 70+ when the speedo shows 70!!!

Speedo's are meant to errr on the side of caution so when it reads 70 you will actually only be doing 68 or so - not the other way around.

Soz!

so when it reads 72.34 mph [55 profile] it will be a true 70..

maybe someone with a satnav/gps and 55's can let us know the true speed at 70mph.. ... - .- -.




Y. O. L. O.
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Well, I do have the 55 and they are dead on. I have a MY2010 and did the calibration in the settings menu. Checked with my iPhone GPS and compared with the speedo

Guess the 55 is approx 4% larger than the 50 Range Rover TdV8 Autobiography MY2010
Defender 110stw Td5 MY2006

No - the other way around - when it reads 70 (speedo) the car could in fact be travelling at 72.34.

However, as all speedo's err on the side of caution the reality is that with 55's instead of 50's the speedo may actually read 70 when the car is doing 70 which is kind of what you said at the end of your post but for a confused reason.

Soz, not trying to be awkward or confrontational.

Yes I think some of you are thinking this the wrong way round , one revolution of the drive shaft ( which is where the pulse for the speedo comes from) on a 55% tyres will result in a grater distance covered by the out side diameter  2008 MY Supercharged
Rimini Red / Jet
four zone climate
remote park heater
and no ugly kid windows.
magnus satis quod turpis satis

Gents, apart from the ratio differences, the speedos always have a few percent difference as well. It used to be up to 10% but seems to have reduced to the range of 2 to 5% mostly.

My suggestion is, to use a GPS speedo app on your phone to see what the real speed is compared to indicated. That way you also account for the speedo indication difference at the same time. GPS speedo is pretty accurate I believe since it is based on super accurate timing and pretty good locational tolerance as well. It would be interesting if someone can actually tell how accurate GPS derived speed info is (I calculated less than 1% off but I'm not a specialist on GPS signals).

Speedos are normally indicating higher speed than you are actually travelling at in my experience and that is from using GPS/Nav apps plus reading many car test reports. Every report I can remember the speed shown on the speedo is higher than actual speed but I won't go into the accuracy of the measurement of the real speed the way it was measured (the used to roll this "5th wheel" contraption behind the cars). MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!