Wheel size change = Altered speedo readings?

[mjb666]

The previous owner of my Mitsubishi L200 4x2 Single cab changed the wheels from the original 14" pressed steel wheels

screen shot on pc

with 185R14 tyres

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to these snazzy looking alloys

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with 235/70R16 tyres

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It seems to me that i'm driving faster than the displayed speed. Does anyone have a simple way of telling me how far out, if at all, i might be?

Thanks

Mike

[zildjian]

buy or borrow a road angel speed camera detector to display your speed

[Mike]

Or if you have a smart phone there are a number of apps linked to the GPS built into the phone which will display speed.
Or a great free navigation app is HERE maps developed by Nokia originally you down load just the maps you need so no streaming charges. I use it a lot when I travel in Ireland in hire cars on business.It displays speed which is the point of this......

[zildjian]

You only need use it for awhile, then add a note to identify where 30/60/70 actually are on your speedo
(or as tractors) work out from rev counter and gear you are in,
how fast you are travelling

[earthman]

Another option maybe, find a place on the dash to mount a Scangauge or similar, apart from giving a speed readout there's other features, it can read/clear some fault codes too,.....all assuming that the vehicle has an OBD2 port in the first place.

https://www.scangauge.com/

[Toshbins]

Mathematically, the new tyres should be only about 1.3% bigger, but a GPS speedo on your phone should confirm it.

[mjb666]

Thanks for all the suggestions, i will checking to see if i actually have a OBD2 port?

[Toshbins]

Whoops. That should read 10.3%.

[zildjian]

somewhere lowdown on dashboard maybe below steering wheel or glove box

[earthman]

Thanks for all the suggestions, i will checking to see if i actually have a OBD2 port?

If it's a 2005 vehicle, it should have one. You may have to remove a piece of plastic/trim to see it first but it should be within reach of the drivers seat, I believe that were one of the rules.