Richard_J

New Member
My disco 2 is currently on road tires... they are 255 55 r18 I was thinking of changing them over to Goodrich T/A KO2. I was wondering if anyone has these tires and if so are they any good. My only other thought was to take of the land rover alloys and go for steel wheels r16 so I can go for a larger side wall profile... any thoughts on that idea
 
Hi Higgo
I thought about a large double tire as that would also lift my diffs up slightly... but I don't at the moment want to start cutting into the bodywork
 
Mines on 255/60 18s
No mods to bodywork etc reqd.
But as wammers says, probably not kosher as the speedo is dead on, or poss a bit under, compared against two GPS units, so no room for error when driving through average cams etc.
 
If you fit those your speedo will be illegal.
I guess the same is true for anyone who uses a larger diameter tyre (depending on whether (and how much) it's currently over) as it will cause it to under-read by ~5%
 
I guess the same is true for anyone who uses a larger diameter tyre (depending on whether (and how much) it's currently over) as it will cause it to under-read by ~5%

In the case of the tyres you mention at an indicated 60 your actual road speed would be 63.1 MPH. But the odometer would also be under recording the mileage travelled which the powers that be take a very dim view of. ;);)
 
I just fitted a set of 255/55R18 Grabber AT and they're mint! My neighbour has them on his truck and after 20K they're still not half way worn. Quiet and grippy on the road too!
 
My disco 2 is currently on road tires... they are 255 55 r18 I was thinking of changing them over to Goodrich T/A KO2. I was wondering if anyone has these tires and if so are they any good. My only other thought was to take of the land rover alloys and go for steel wheels r16 so I can go for a larger side wall profile... any thoughts on that idea
It's tyres....

;)
 
Wammers knows his stuff on the %, Mine is indeed out by 8.9% with my Dynopro M/T's just take it easy around speed cams and averages, go the same speed as others and you can't be much wrong there! ;)
 
Working out the percent is easy, it's just maths.... but it's still guess work unless you know the exact diameter of the tyre. Not all tyres of the same rated size are actually the same.

And there might be requirements for brand NEW vehicles to pass Type Approval to meet certain standards, but changing wheels on an older vehicle has nothing to do with type approval.

And when most modernish vehicles tend to read around 10% low on the speedo to begin with, there is plenty of scope to still be within a threshold.
 
And when most modernish vehicles tend to read around 10% low on the speedo to begin with, there is plenty of scope to still be within a threshold.
I find the error on most modern speedos to be negligible, dependent simply on tyre wear. Even my 2 decade old disco manages better than 10% accuracy, somewhere around 5-6|%. Ye olde mechanical speedos tended to be set quite over, but of all the newer cars I have rented or driven in the last few years, not one has been out by more than 1mph at 30. an error in the region of 3%, not 10.
 
No it wouldn't. And it's not as if they are 100% accurate to begin with.

If the vehicle was made 2001 or later it would. From 2001 on it is illegal for a speedo to read slower than the actual road speed. The vehicles road speed can be 10% slower than indicated but not faster. At an indicated 30 MPH with 265/60/R18 tyres fitted his road speed would be 31.5 MPH, at an indicated 60 MPH his road speed would be 63.1 MPH therefore his vehicle would be illegal.
 
If the vehicle was made 2001 or later it would. From 2001 on it is illegal for a speedo to read slower than the actual road speed. The vehicles road speed can be 10% slower than indicated but not faster. At an indicated 30 MPH with 265/60/R18 tyres fitted his road speed would be 31.5 MPH, at an indicated 60 MPH his road speed would be 63.1 MPH therefore his vehicle would be illegal.
It was made in 2000. Still illegal?
 

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