Compare your RPM at 100 Kms speed

[haffeel]

Genlemans/Ladies,

I want to know if my E30 320i Auto is running as it supposed to, by comparing notes with similar engines in this forum.

On flat road running at 100Kms speed, my RPM is at 3000 or little above. Is this OK.

A friend of my mine claims, my gear is still running on 3rd gear and I am wasting good petrol. By right he claims, at 100Kms speed, the RPM should be 2500 and I should be on 4th gear. Is that correct?

Can any one post your readings for comparision.



cheers

[smithy318i]

100 Km per second wow, wish mine went that fast.

[haffeel]

It is suppose to be 100Kms/hour speed my reading is at 3000RPM

[StuBeeDoo]

Genlemans/Ladies,

I want to know if my E30 320i Auto is running as it supposed to, by comparing notes with similar engines in this forum.

On flat road running at 100Kms speed, my RPM is at 3000 or little above. Is this OK.

A friend of my mine claims, my gear is still running on 3rd gear and I am wasting good petrol. By right he claims, at 100Kms speed, the RPM should be 2500 and I should be on 4th gear. Is that correct?

Can any one post your readings for comparision.

cheers

First of all, what year is your car? If it's a '88 or later (face-lift model), you should have approx 3700rpm at 100km/h in 3rd and approx 2750rpm at the same speed in 4th. These figures assume that you have the 4.27 diff.
What you really need to do is check the tab (which should be attached to one of the diff rear cover bolts) to ascertain which diff you've actually got and work it out from there.
HTH
Stuart.

[haffeel]

Thank you mate for some solid info.

My E30 is 84 model but the engine is year 88 320i. Not sure what differential in use. Will check today. In case my differential is not the 4.27 then changing to one will it be a big problem? I will ask my mechanic today.

TQ/cheers

[StuBeeDoo]

No problem. If you post your findings here, I can work out the relevant engine speed - road speed equivilences for you.
Stuart.