Outer Limits 4x4 Board

Ok, long story short...

My YN65 needs to be engineered for (amongst other things) the 33x12.5x15 tyres, to do so I must have the speedo must read correctly.
At the moment when the gps says the old girl has struggled up yo 100km/h the speedo reads 85km/h. I asked around different places and people but no body can tell me what percentage the speedo is out by. I cannot find a tyre placard anywhere on the thing so I don't even know what the standard tyre size is, so I cant use an online speedo calibration calculator bizzo.

Now please dont laugh... Am I correct in assuming that 100 - 85 = 15... Therefore its 15% out??

Has anyone used a ratio box on their hilux, if so do you know what ratio it was????

any help would be greatly appreciated

Hey mate, you add the gearing to the original speed. Eg. For a 16.5% recalibration box - 85km/h x 116.5% = 99.025km/h on the speedo. Snake sell that ratio. Marks can probably get them too

Thanks very much for your help.... that makes much more sence I'll check them out now (and probably end up buying heaps of outer stuff whilst i'm looking lol)

Been doing similar things myself. My truck has ended up the opposite die to deliberate overcompensation with the gearing, ie: speedo reads 100kmh but gps says 114kmh...

Anyway, marks said they dont care what its out by just figure it out, let them know and they will send you a box to suit your car..

sounded pretty good to me