speedo reading incorrectly..

[crshbndct 0]

so my speedo i reading a bit high.

when it says 60kmh i am doing 48.. when it says 110, i get passed by trucks. and it feels like i am going very slow. however with the tolerance being put down to 5kmh for the holiday weekend, i didnt want to risk going much faster.

its a bloody pain having no idea what speed your doing. it only seems accurate to within about 10-20kmh.

car is a 1988 320i(pre facelift) with a 3.91 diff. not sure what gearbox is in it, but would guess getrag 240? so whats the deal?

[Forrest 35]

What wheel size + tyre size are you running

[greenday-rulz21 6]

^^ Pretty much what it will most likely come down to. E30 speedos are also notoriously inaccurate.

[e30ftw 410]

Mine is exactly the same. 60kmh is 48kmh (according to those speed boxes that show your speed).

Understandable though as I am running 205/40/16's which has a smaller rolling diameter than stock. If your using the right tyre size your speedo is probably just farked..

[crshbndct 0]

stock bottle caps with 195/60/14

[my_e36 43]

Isn't there some place that you can put on a rolling road to have that verified?

If you are actually doing 48km while indicated 60, you will never done for speeding for sure!

[Shady 0]

Mine says 60 is 57 so mine is only 3ks out

[cliffdunedin 8]

The older magnetic speedo's tend to weaken over time, what could be your problem! If i were you i'd borrow a gps off someone and then measure yourself on a straight flat road at 100kmh, then adjust your speed accordingly...those signs that say how fast you are going are ok but again can be out by a few kms or replace/check speedo/cable etc

[JiB 0]

stock bottle caps with 195/60/14

Am pretty sure that's the wrong size, that's a 316/318 size. Pretty sure all 6 cyl's run 195/65r14.