speedo reading?

[greg1.4]

just interested to see if my brothers 2.0 nova had an accurate speedo reading. We took it a run (on a private road though) and it said it was doing 136mph on a digi dash with the matching engine and gearbox out of a astra gte? It was a 2.0 16v and had 15'' fox wheels wheels with some gas struts, lowered 40mm and had cheap "budget" tyres.lol

It was also flat out in 4th gear. Anyone think this would be right or is it way out? Had a full janspeed system on her too.

[Philsutton]

no speedo is accurate, sadley you will find that you were probably doing 120ish real speed

[Jim Mcrae]

get some satnav, then see what tyhat reads:D

[Adam]

A digidash shouldn't be too far off true speed tbh.
No mechanical losses etc.
electronic.

Altho tyre size etc will effect it.

[Stuart]

see speed in gear on sig link