Is it normal for a 1990 mazda miata to go 70 mph at 4500 rpms in 5th gear?

i was on the freeway and noticed the high rpms.does the transmission have another gear? if so at what point is it supposed to shift in to it?Is it normal for a 1990 mazda miata to go 70 mph at 4500 rpms in 5th gear?
That is not a normal RPM for a 90 Miata. I do 85mph in my 91 Miata and I do not hit 4,500 RPMs. Heck mine stays around 4,000 RPMs at 85 mph. So I would say you need not only a tune up, but a full service to see why your having this kind of issue.
no is not normal

5 gear if manual trans, turns two times while engine turns one



that means 70mph = 3500rpm

so the question is did you feel your car with no power? because is everything is ok maybe you need a new cluster or the speed sensor is bad a ecu will help a lot because that is an electrical issue (that is assuming your engine is good on compression and your car is MANUAL trans)



if it is an auto trans.... that is your problem your trans, take the car to a trans shop and get it checkedIs it normal for a 1990 mazda miata to go 70 mph at 4500 rpms in 5th gear?
Of course no this is not normal ,,,



for sure it should be 2300 rpm at 100 km/h



that means at 115 km/h (70m/hr) the rpm should be around 2600 rpm.
Check your car speed in each gear at say 3000 rpm. My guess is that you are shifting back into 3rd gear instead of fifth. Customer brought a car in with a similar problem. He was going into 5th when he shifted to 3rd and wondering why the car was bogging. Make sure clutch is not slipping.Is it normal for a 1990 mazda miata to go 70 mph at 4500 rpms in 5th gear?
I take it that you are either driving an auto-matic, or maybe your clutch is slipping.

At 4500 rpm in 5th I am close to 90 mph.

There is also the chance that someone changed the rear end gears.

Speed in a car is determined by the rpm and gear ratio. So it is not a tune up problem.

1990 miatas for twice the fun
That is really high! No there is not another gear 6 speeds did not come out until 2005 speedmiata. You have a problem and you need to get it checked! And it is not a problem that is going to be answered on Yahoo answers cause it can be a multitude of issues.