2020 GXL Speed Change /Tyre size

[meatman61 Junior Member Find all posts View Profile Close meatman61]

We have just traded our 2011 150 in for a 2020. with the old one, by upgrading the 265/65, to 265/70 tyres, the speedo was correct. The new one is all electronic, can anybody tell me if doing the same tyre upgrade on the 2020 model, will the speedo/gps , still be correct. It is spot on with the factory 265/65 tyres. Thanks.

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

The bigger size is about 5% different so if it is spot on now(unusual) you will be doing 105 when Speedo says 100. Check with a sat nav and or an app or 2

[rascal Member Find all posts View Profile Close rascal]

Yes, the same tyre upgrade will still affect the true speed as before. Electronic or mechanical speedo doesn’t change this.

as 404pug said, use a gps to confirm true speed.

[Leethal Advanced Member Find all posts View Profile Close Leethal]

My Oct 2018 build VX speedo reads 5% low at 100km/hr with the standard 265/60/18s, with the set of 265/70/17 Yoko LTs I have for outback touring fitted the speedo is accurate at 100 km/hr however the odometer reads under for distance covered. That the odometer is accurate but the speedo is not is something I have found regularly with late model cars, I believe it is the manufacturers designing in an fudge factor to ensure they meet ADRs re speedo accuracy.

[Guest Close Guest]

Every vehicle is different, only way to know exactly is to try it. Last one I did (2019) going to a 70 series saw the speedo go over. 110 indicated was 113 in real life. Whereas the 2014 I did was dead accurate. My 2006 was also over by 3kmh.