I've noticed while driving in 6th gear on the highway travelling at about 110KM/hr(65mph) the RPM is no less than 3000.

I would expect a lower RPM from a 2.4 litre with a 6-speed.

Is my car behaving normally?

 

 

Dan is correct. It has to do with the gearing of the MTs

In ATs it is a good deal lower (I think mid 2000s)

 

I love close ratios but this is a bit too much for the 6th gear. They should've made the 6th gear bigger.

 

IranBT:
about the same, but slightly different than my recent RPM test ( I used cruise control to hold the speed to verify RPM)
From my reply to: m/t tsx rpm at 60mph?

on my stock 2006 6MT:

2rd gear - 60 mph at ~7300rpm
3rd gear - 60 mph at ~5400rpm
4th gear - 60 mph at ~4000rpm
5th gear - 60 mph at ~3400rpm
6th gear - 60 mph at ~2600rpm
(also 6th - 68 mph at 2800rpm to compare with other reply)

 

that seems tame. i am used to my old prelude going 70 or 80 pushin 3.5 or 4k respectively.

 

That's very discouraging to me. I guess mine is running too high. f****. I hate to have the engine touched when the car is less than 1 week old.

I'll do some more research.

 

It may be possible that your tach or speedo is a little off. If you have aftermarket wheels/tires that will also affect the engine speeds. These are the exact numbers if you want to confirm your findings:

At 110km/h:
1st: 14028rpm
2nd: 8073rpm
3rd: 5818rpm
4th: 4414rpm
5th: 3542rpm
6th: 2830rpm

I can email you my spreadsheet if you'd like to try other speeds. Just PM me your addy...

 

They do have it geared a bit high strung. The engine is capable of pushing the car at 70mph without having to spin 3000 RPM. This is one of the few design features of the TSX that needs a bit more attention IMO. The gear ratios ought to be rethought--with first being a bit taller, and a bigger spread between 5th and 6th, among other things. I'm not always running a freakin 1/8 mile track...

 

Thanks for the info. I have no aftermarket tires. I have a fully stock 06 and by these numbers, there's definitely a problem. I can't imagine this being related to the car being new, or am I wrong?

And to be exact, my RPM is at 3000 when I'm going just 100(not 110) which should explain the slightly poor gas-milage I get on the highway.

This is bothering me so much now. I don't want to go to the dealer before I'm certain about this.

 

To check the speedometer, get a friend (esp. one w/ a TSX if you can!) and drive side-by-side on a 4-lane road, and pre-agree on a speed to set the cruise to once you're window pillars are even. Say 90km/h or whatever is legal. Then see who pulls ahead of who... once that's determined, the person in back should speed up to the other person and peg their speed at theirs... then you'll see the difference.

+/- 3% is acceptable.

 

Dan how did you get your exact numbers? is that from the NAV or a dyno? or something else?

according to my calculator 110km/h =68.35mph

BTW for my RPM @60MPH numbers are approximated by my eyes on the meter (cruise) and I have new YOKO tires but stock size 215/50/17s my car is at 9,300miles-4months old.

 

Just as an FYI, I recently drove 1400 miles (2250KMs). I was pleased to note that with my '06 5AT (I know, I know), I could cruise at 75mph (120KM/hr) at a peaceful 2600 rpm, or thereabouts. And I wound up with 33.2mpg. Sorry, I'm too lazy to do the KM/100L (I think it is) conversion here.

I've had the car a couple months, and love it. I can't quite get the "Should I have gotten the 6MT?" question out of my head, though. But the above info kind makes me feel better about my choice. (Sorry, IranBT.) And my previous three cars were sticks, so I'm definitely enjoying the AT during commutes.

 

Its a function of tire OD (from manufacturer's specs), final drive ratio, and gear ratio. If you'd like my workbook, just send me a PM. It covers both 5AT and 6MT transmissions.

 

Your observation sounds pretty close to what the calculated speed should be. At 75mph in 5th gear on a 5AT, it should be 2488rpm. There's probably a little rounding within the calculation, so +/- 200rpm isn't bad.

 

I think that the gearing is the way it is to maintain good throttle response at highway speeds. With the TSX developing more power and torque as the RPMs increase, keeping the revs a little higher prevents having to drop from 6th to 5th (or 4th) at highway speeds to make a decently quick pass or other similar manuver.

I've noticed that at 70 mph, I still have reasonably good response in 6th gear. Not sure that would be the case if the engine was running 400 or 600 rpm lower. I agree its a little high strung, but remember, there's a tradeoff with everything.

 

I'll agree with 5th being good for 3542rpm @ 110 kph, if you say so, because that equates to 220 at 7100rpm, but you know what they say about if you have time to look you aren't going fast enough, even if the road wasn't straight.

 

I love the fact that the revs are higher then they really should be when cruising in 6th. Makes passing easier without having to drop to 5th all the time...

 

Yeah my buddy's integra type-r would be hitting 4k or so at 75

 

Im sure the car thieves will find that one out themselves some day

 

Just had a drive in my TSX and I think my RPMs are much closer to what they should be than I originally thought. This is a huge relief as I was sadly preparing to leave my car at the mercy of Acura's mechanics.

I still think the 6th gear is not set up for best economy when in reality it should be. I can't imagine myself trying to pull a crazy catch-up in 6th gear. The whole point of having a manual tranny is to be able to downshift at will. This explains TSX's relatively poor gas milage. High reving top gears.

Thank you all for your replies.