Speedo is out of whack.

[heuge65]

Made a discovery last night, I've had this terrano.. 2-odd months now and I've felt it was driving 'slow', ran up my gps last night and headed out. So when my speedo says I'm doing 40km, gps has me at 35km. speedo=50km, gps=44 and so on. Quite a marked difference I'd say and even given the discrepancy of both sources of speed information I'd say there's something wrong there.

So, looking at the truck, I have the feeling she might be 'lifted' a little, I'll climb under this evening when my young fella gets back with it and have a look, can anyone suggest where and what I should be looking at to check that?

Second, I would think it was running larger tyres, it's still got the standard rims and I've chucked normal road tyres on it, what is the largest tyre you can go to with standard rims? I'm a beach-head and don't usually head into the bush, I'm more likely to be found out on Muriwai, the Kauri coastline or the 90 and the like. Do the larger tyres come out in in normal road tread (better for the beach)? Is that worth it? Running larger road tyres?

Lastly, if I'm to have the speedo recalibrated, what kind of a job is that worth? I'd say it's chewing through the RUC kms quicker as a consequence so I'd like to know my options.

[Sadam_Husain]

4-5km difference isnt unusual for most vehicles mate, I think I've read on here there are a couple of different ratio terrano speedo drive gears for different diff ratios so you could always look into that

[heuge65]

Yeah, this is 4-5km out at low speed already. There's a few after market things in this truck that make me think one of the previous owners was a good keen man!

[bruntonjm]

Maybe you are running bigger tyres, this would then throw the reading out....

[Dirtydog]

mine was running like that aswell, except when i thought i was going 100, i was going 80.

this was with standard tyres, and ratios, factory truck.

it wasnt untill i put 33's on it that it started fixing it, but unfortunately only by 10 ks, so now i was doing 90.

what fixed it completely was running 4.11 ratios with 33's and a safari transfercase....

[keithal]

Maybe you are running bigger tyres, this would then throw the reading out....

wrong if the speedo is reading 50 when the gps says 44 it would have to be smaller tyres as you are travelling less distance per rotation and therefore slower than the speedo reading

[Suza]

Most cars are 5 - 10% out on their speedo reading from factory as they arent calibrated just bolted in and their is no allowance for what diffs ect are then put on

[heuge65]

It's running at approximately 113kmh when the GPS reads 100kmh. I'd say that falls outside the 10% but more than that, it's noticeable at low speeds so I'd say there is a problem, I'd hoped someone might be able to point the way ahead, recal' the speedo or jump to bigger tyres. Might go see the firestone guys on the weekend.

"Second, I would think it was running larger tyres, it's still got the standard rims and I've chucked normal road tyres on it, what is the largest tyre you can go to with standard rims? I'm a beach-head and don't usually head into the bush, I'm more likely to be found out on Muriwai, the Kauri coastline or the 90 and the like. Do the larger tyres come out in in normal road tread (better for the beach)? Is that worth it? Running larger road tyres?"

[keithal]

has it had any sort of body or suspension lift?
if not the largest you would want to go is 31"s which will fit fine on the factory rims. you can get road/at tyres in 31" pretty cheap as well.
cheers

Alex

[heuge65]

Thanks Alex, exactly what I wanted to hear.