tvr s2 speedo accuracy testing results
Discussion
on a thrash last week in the s2 i got to wondering how accurate my speedo was, because even though the top speed indicated on the car's speedo that day was only 120, it felt more like 140-150! so either (a) i'm getting old, losing my nerve, or (b) the car just feels like it is going much faster than it really is because it is low, twitchy and nervous compared to my bmw 5 series at those speeds (which as the opposite effect, the big beemer is so stable and smooth that you can think you are doing 80 or 90 and look down and see you are doing 120 or 130!), or lastly (c) the speedo is very inaccurate and indicated 120 really was more like 140!
so today i had a 200 mile round trip to go and collect my lsd (woo hoo!) and decided to take the opportunity to test the car's speedo against a really nice little GPS speedo which works just like the speedo on your sat nav but is just a speedo!
the results are interesting (i think), up to 80 the car speedo very slightly over reads, so indicated 67/68 is actually 65.5 and indicated 70 is 68.1.
when you get to indicated 80, it is bang on! indicated 80 and a bit (there are no markings between the 10mph marks) was actually 80.2
and as you get faster over 80, the more the still remarkably accurate car speedo under reads! so 80 is obviously where it is 100% accurate.
indicated 100 and a bit was actually 101. i could test higher than this as it was raining and there was a lot of traffic, but sadly i doubt that the indicated 120 last week was actually 140+
so today i had a 200 mile round trip to go and collect my lsd (woo hoo!) and decided to take the opportunity to test the car's speedo against a really nice little GPS speedo which works just like the speedo on your sat nav but is just a speedo!
the results are interesting (i think), up to 80 the car speedo very slightly over reads, so indicated 67/68 is actually 65.5 and indicated 70 is 68.1.
when you get to indicated 80, it is bang on! indicated 80 and a bit (there are no markings between the 10mph marks) was actually 80.2
and as you get faster over 80, the more the still remarkably accurate car speedo under reads! so 80 is obviously where it is 100% accurate.
indicated 100 and a bit was actually 101. i could test higher than this as it was raining and there was a lot of traffic, but sadly i doubt that the indicated 120 last week was actually 140+
Edited by drak ula on Friday 29th January 17:04
good point, this is with the blurinses 205/60x15 at 24psi on the back. you should get one of these little gps do-dads, only 60 quid or so, wireless, totally unaffected by tyre/wheel size etc.
mk1fan said:
The speedo in the Reserve S is pretty inaccurate.
When comparing to the sat nav. Speedo is 5mph out at 30mph, about 7mph at 60mph but bob on at 80????
Some of the inaccuracy is down to the 195/55 tyres.
When comparing to the sat nav. Speedo is 5mph out at 30mph, about 7mph at 60mph but bob on at 80????
Some of the inaccuracy is down to the 195/55 tyres.
my tomtom has a speedo too but so many other figures going on with eta, current time, distance still to go etc etc it's had to see the speedo in the corner, the gps speedo has a nice big read out you can put right in your field of view as you can see in the pic. it clips out of the suction arm so you could just velcro it to the dash if you preferred.
mk1fan said:
Bit like the satnav I have.
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