Top of the mornin to all, what do you guys believe is NORMAL
when runnin @ a good highway speed?

Had mine on the interstate yesterday, the RPMS WERE @ 3000
JUST SEEMS A LITTLE HIGH TO ME.

 

From my XJS V12 days ....1988 coupe in my case...I recall that 80 mph was exactly 3000 rpm and 100 mph was about 4000 rpm

Cheers
DD

 

That's about mine too.
This thing's 3 speed transmission just does that

 

On the race course I'm sure

 

closed course in mexico.


no overdrive will do that.

 

I had an 88 XJS also and I seem to remember 80mph being 3000 rpm. I also remember 150mph being around 5800-6000 rpm.
(non race course) =)

 

my gear calculator says 3272 rpm @ 90mph with a 2.88 rear and stock tires. I would add 300-400 rpm for torque converter slippage, so in reality, the tach will probably read 3500-3600.

At 100 mph, it says 3635; 4000 is probably on the tach with slippage.

 

i find that in third gear in my '87 coupe, the speedometer and tach are almost synonymous.

 

in my dads old civic, 4th gear and the Tach were in perfect sinc.