The 75 and ZT Owners Club Forums - View Single Post

arnosvale65 · 7th September 2015, 17:57

I have a Scan gauge permanently connected to my OBD2 port and it, like everyone's sat nav, shows an error of 3mph at 30 and 5mph at 60. While talking about this subject does the law still allow 10% error for speeding or has this come to be a generally understood phenomena due to all our speedos over reading?
In my trucking days I always kept my truck on the limiter(55mph) and never once got pulled up for speeding in roadworks. Due to what I have read on this thread about speedos being set to read higher than actual speed in a truck this is downright bad practice. With a digital tachograph any speed over the limit(85kph) comes up as an overspeed and UK police have been known to issue fines and points on this evidence. This speed is actually below the speed limit for trucks on motorways which is set at 60mph. How can that make sense? I know it is an EU rule (85kph) but the Spaniards have an exemption. Why don't we?

7th September 2015, 17:57	#23
arnosvale65 Posted a thing or two 75 facelift CDTi Connie SE Tourer. MGF 1.8 VVC Join Date: Jul 2014 Location: bristol Posts: 1,424 Thanks: 176 Thanked 176 Times in 119 Posts	I have a Scan gauge permanently connected to my OBD2 port and it, like everyone's sat nav, shows an error of 3mph at 30 and 5mph at 60. While talking about this subject does the law still allow 10% error for speeding or has this come to be a generally understood phenomena due to all our speedos over reading? In my trucking days I always kept my truck on the limiter(55mph) and never once got pulled up for speeding in roadworks. Due to what I have read on this thread about speedos being set to read higher than actual speed in a truck this is downright bad practice. With a digital tachograph any speed over the limit(85kph) comes up as an overspeed and UK police have been known to issue fines and points on this evidence. This speed is actually below the speed limit for trucks on motorways which is set at 60mph. How can that make sense? I know it is an EU rule (85kph) but the Spaniards have an exemption. Why don't we? __________________ Onwards and upwards. MGZT-T MK1 front and rear ends fitted, specialist- components in line thermostat mod done, retro fitted cruise control, Mk1 real wood dash fitted, real walnut steering wheel fitted, Pioneer DAB radio fitted. Last edited by arnosvale65; 7th September 2015 at 18:02..