highway rpms

aright so recently, ive been doing alot more highway driving b/c my jobs in the city. anyways, ive noticed when im driving that my rpms seem to be quite high(even for a 5-spd). my rpms are- 3.6k at 70mph and 4.2k at 80 mph. and usualy i cruise at 80 when theres no traffic. is this the norm for preludes because no other 5-spd ive driven, rides this high. also, since im cruising at 4k, could this be guzzling my gas or putting wear on the engine????

fairly normal although seems jus a tad high. 80mph = 4k for me and 70 = 3.5k and 60 at 3k

that's normal, ain't hurting a thing :smile:

I've been doin some highway driving recently too, and my 5th gear hits vtec at 100mph. and when i'm cruisin around 90 i'm at 4k+ . I wasn't sure if that was normal or not.

oh okay. u guys know how gas mileage is on highway at these rpms???

I got the automatic, and its funny you posted this, because I notice things like this. And my buddy has a manual 01 lude, i have a auto 97 lude. And when i was riding with him the other day i noticed that the manuals RPMs run a little higher then the Auto. I thought it was a little wierd. Mine is 3600rpms at 80 mph and every 500 rpms or so gives me nother 10mph

its just the way the gearing is set up in the lude.
shorter gears = quicker acceleration
longer gears = better gas mileage

driving highway at 70 mph I get around 27 mpg

Its not much so the high RPM's that will kill your gas mileage. Its how "heavy your foot is".

Think of it this way...on the H22, 70-75 mph is at about half your redline, or half of the engine's rev ceiling. Now what about your average car that is at about 2.5-3k rpm's at that point? It's about the same ratio. Our motors rev that high, because giving us that much longer of a 5th gear ratio would make it so the car would barely accelerate in 5th. Having it like that puts you in the right band so that once you shift into 5th it's still pulling.

That's why the si and s have progressively taller gearing. The farther you move away from the sporty close-geared cars, the more gearing shifts toward gas mileage and the farther they let your rpm's drop on and upshift. It's just a trade-off.