JRock

What's up with the TSX's gearing? It doesn't have any real overdrive gears. If they had a better 6th gear, the thing would be in the 30s for fuel economy.

2600rpm at 60mph
3000rpm at 70mph

That's pathetic.

Yes, I just test drove one to get re-acquainted with it. =p

95gt

would be in the 30's but you would have to downshift 4 gears to get it to move at all. Hey as long as i can't hear the engine buzzing i am fine with that.

ClutchPerformer

Not true. Auto TSX owners have a taller top gear. I've never heard one of them complaining about having to downshift at highway speeds.

fdl

6MT is geared strictly for performance, not for fuel economy. I would have liked a taller 6th gear. On the plus side though, I never have to downshift on the highway.

JRock

That's retarded though. 5th gear should be the "performance-geared" highway gear.

Uhm no, all you need is 6th to be a taller over-drive gear for highway use like most 6-speed sedans have.

95gt

Uhm as this is a low torque 4 banger the less rpm's you have the less go you will have on tap? besides V8s like the corvette most are not as tall as you are indicating (WRX/STI come to mind. They are almost at 3k at 70 as well.

Jab31169

Yea...so anyways....I get an average of 31mpg on the interstate and Im more than happy cause at that rpm it puts you right in a nice powerband so you dont have to downshift to pass. and even if 6th was taller that would put you in the mid 2500's at 70 and you would maybe squeeze 1-2 more mpg. Please think about something before acting like you know more than you do.

sauceman

Well you can always take a look at the mileage I do with my 6MT in my sig. It's not that bad.

Like fdl said, if you want a taller 6th gear, get an AT, or maybe buy a Matrix... with all the unsportiness it comes with.

JRock

Hahahah naw. The mpg/rpm in 6th is about the only thing I dislike about the TSX right now. Other than that, it's a nice car.

I'm looking at other totally different cars too though... '04 Mustang SVT Cobra, '02 (used) Audi S4, '04 350Z, etc. I certainly wouldn't be pushing a Matrix. =p

Lung Fu Mo Shi

If you can handle the small size, get the 350Z. The others are maintence problems and won't handle as well.

Just my opinion.

ClutchPerformer

6th gear has little to do with performance...

Is anyone else getting deja vu?

buzzdsm

I just sold my 03 350Z and it had some serious tire issues. Go over to my350z.com and do a search on tire feathering. About half the owners are having issues and Nissan can't figure out how to fix the problem. Driving below 30 mph and it sounds like you're driving bigfoot. Other then that I loved it but it's not a good daily driver. It would make a great 3rd car which I can't justify.

Currently I'm tryiing to decide between a Accord V6 coupe and the TSX (isn't everyone?).

iTimmy

There is a thread about that exact topic- of course the users here are bias towards the TSX, but I don't think you can lose with either car.

TinkySD

is there anyone else that would take a g35c over a 350z straight up?

kiteboy

That's a no-brainer. Better styling, more lux and a back seat.

gilboman

um...you realize the WRX is a 5spd right?

buzzdsm

I bought the Z so I guess you know my answer. The interior of the G is nicer but the Z is more of a sports car and it looked nice. Here is what mine looked like.

idlegrasshopper

Unless you get some of those gears that magically change the laws of physics, simply dropping the revs in 6th gear isn't going to give you better fuel economy.

fdl

What do you mean? Lower gear ratios will yeild better mileage numbers. Thats why the 5AT is more feul efficient. Bottom line is cruising at 2500 rpms will not consume as much fuel as cruising at 3000 rpms.

If you think otherwise I'd like to hear why.

SPUDMTN

Definitely. But I wouldn't want either of them in the first place TL me, please Heck--A4 me before the G35...

G35 = Chintzy interior

TL = perfect balance of sport & lux

A4 = BEAUTIFUL inside and out. The non-status, status symbol

ClutchPerformer

Then I guess the 5AT TSX has some of those magical gears....

budzzz

The gearing is fine. Leave it alone! I travel through the mountains a lot and I have to drop a gear or two when going over the passes. If you had taller gearing, 6th would never get used in my car. On my last trip to Denver I got 33mpg. Best ride I have ever owned by far!!!

ClutchPerformer

OK. Most people *don't* travel through the mountains a lot... We would benefit from a taller 6th gear ratio.

What is the point of having a manual transmission that you don't want to shift?

idlegrasshopper

Traveling at 70 mph requires some amount of power, lets say 15 hp for this example.

Regardless of the engine speed, 15 hp is still required to move the car at 70 mph.

That means that the engine will and must produce 15 hp whether it is running at 2500 rpm or 3000 rpm.

The only way the fuel economy will improve when you change gear ratios (thereby changing engine speed for a given road speed) is if you move the engine to a speed at which it is more efficient.

Given the high-revving nature of the TSX engine, and the fact that the peak torque is somewhere around 4500 rpm, it is doubtful that 2500 rpm is a more efficient speed for the engine than 3000 rpm. Without an engine map, though, this little nugget of the discussion is conjecture.

That being the case, a different gear ratio in 6th that drops the revs from 3000 to 2500 at 70 will not improve fuel economy, but would instead make it worse.

You might wonder why the engine would use less fuel at 3000 rpm than at 2500 rpm, because at 2500 rpm means 500 fever rpms, and doesn't that mean that you'll use that much less fuel? Not exactly, because fuel economy depends on the throttle position, i.e. the amount of fuel going to the engine. This goes back to the engine efficiency. Every engine has a speed where it is most efficient. That is the speed at which is does the best job of extracting the energy in the gas and turning it into a force which drives the wheels. That means that it is possible to produce the same amount of power from less gas at a higher rpm if the engine is more efficient there.

As for why the auto produces better numbers on the EPA test than the manual, that's a whole other issue, as an automatic is less mechanically efficient than a manual, even with the torque converter locked up. Since the EPA mileage test is a standardized test, and since electronic controls are smarter than people for specific tasks, it's not inconceivable that the computer has a special "EPA mileage mode" that senses when the car is being tested and optimizes the performance just for that test. But before I talk too much about that, I have to consult with my friend on the grassy knoll

My disagreement with the lower rpm=better mileage people is intened to be based on facts and physics, not on what my opinions are. I thought the same way some do, until I really delved into the subject. I'm just trying to dispel some myths and edumacate others.

ClutchPerformer

You're not listening....

The 5AT TSX is essentially the SAME CAR as the 6MT TSX. It has a taller (numerically lower) top gear ratio. It turns less RPM in top gear and gets BETTER gas mileage on the highway (even though it's less mechanically efficient). These are facts which go against everything you've spent so much time saying.

SO: the TSX engine HAS enough power (to use your example, at least 15 HP) at a lower RPM to move the car at 70 mph--the 5AT has demonstrated this.

The analytical approach is nice, but you're overestimating the effect that throttle position has on fuel consumption.

TSX Hokie

idle,

By your ridiculous argument, you would use the same amount of gas going 70 MPH at 6000 RPM (or whatever it happens to be) in 3rd gear as you would at 3000 RPM in 6th.

Try never shifting above 3rd sometime for a whole tank of gas and tell us what kind of mileage you get.

I think Honda engineers put alot of thought into the gear ratios, and came up with such a short 6th for a reason. How cool is it that you can maintain 70 MPH in 6th with the cruise control, even going up a steep grade with 4 passengers. The short 6th makes cruise control a lot more valuable. I still get 30-32MPG on every tank, so I can't complain.

ClutchPerformer

Very cool.

...But I think getting better overall highway MPG is cooler. Again, I don't hear the 5AT owners complaining about their trannies deciding to downshift at highway speeds. And even if it is needed, what's so wrong about downshifting every once in a while? It'll keep us from at the wheel...

OT: Hokie, I gather from your posts that you're an ME student? What are you doing research in? PM me if you want.

95gt

Was just talking about the final gear (be it 5 or 6). Sorry:P

idlegrasshopper

No, I wasn't. Sorry. My dad always yelled at me for not listening as a kid, and I guess I haven't gotten any better as a grownup.

Lung Fu Mo Shi

I don't. Although that could be in large part to my full throttle hill climbs (10% grade) every day going to my apartment.

TSX Hokie

Cruise control is your friend when it comes to fuel economy.

sauceman

I can understand your point, and it could be true if the TSX was dramatically overgeared, as in 1500rpms at 65mph, but going from 3000rpm to 2500rpm at 70 will help fuel efficiency, since at 2500rpm, with the help of a good aerodynamic efficiency, the TSX engine is torquey enough to improve it's mileage.

And note that usually, an auto tranny is, as you say, less efficient in transmitting the torque to the wheels, thus, opposite to what you say, by nature, less fuel efficient than a manual tranny. What makes the 5AT more fuel efficient in the case of the TSX is 2 things:
1. Longer final drive
2. The ECU commands prompt upshifts while in drive, minimising the revs, and making it burn less fuel in one given distance.

kiteboy

I don't know the specifics of the EPA test, but the Transport Canada highway test is: acclerate to 96km/h, cruise at 96 km/h for 15km (no stops), and then stop at the end.

That's a fairly representative (abeit slow) profile of highway driving, which means if a car is engineered to perform well at the test, it should do well in the real world also, especially with cruise control.

It's interesting to note that the TSX scored 38 mpg (MT) and 42 mpg (AT) in this test.

joerockt

Im very happy with the gearing on the 6MT. 3K @ 70mph is perfect for that engine. Since it doesent have a lot of torque, you can still get up an go on it in 6th. If it was a lower rpm, you would find yourself hitting the gas harder to accel, or downshifting. Im getting about 28mpg, but I dont drive highway very much since I dont have to take one to get to work. Kinda nice when your only 5 miles from work

As a side note, I was driving home lastnight from a concert and hit 120 very easily from 80 in 6th...and I was only running about 4.5K rpm. Awesome

TSXSTI

I wouldn't mind a slightly longer 6th gear since I don't mind downshifting on the highway. That's why we bought a manual. Actually, it's my wife's car and I drive it once a week, so whatever you guys come up with is fine with me .. lol

As for whoever brought up the STI revs, yes, it does rev pretty high at 70mph .. about 300 rpm less than the TSX tho.

ClutchPerformer

Shifting is the reason why you buy a manual transmission.

joerockt

Thanks :captobvious:

My point was, you dont HAVE TO shift when crusing at 70 to get to 80 or 90 quickly. Sure you could drop to 5th if you had to get out of the way of a merging truck or something. But for general passing, 6th works just fine.

ClutchPerformer

Yeah. And your highway mileage takes the hit.

jimby

The current US EPA highway mileage test runs the car at an average highway speed of 48 mph. This is one of the reasons why there is currently a movement to update the test to reflect real world conditions.

It would be interesting to compare mileage for both 5AT and 6MT at real highway speeds. For instance, I just got back from a trip where I averaged 67 mph on the way home and my mileage was 32 mpg. (I have a 6MT.)

Any 5AT owners out there with similar stats?

ClutchPerformer

I get 32-33 mpg on the highway, too. Autos get more.