Transmission question

honda
accord

#1

Hello everyone, this is just a general question. I drive a 2002 Honda Accord, 5-speed Manual, l4. I’ve been driving this car for about year and my driving consists of mostly driving to the college campus and back (mostly city). However, when I do get on the highway, and I’m cruising in 5th gear at 65 mph, the rpms run at 2,500 rpm or so, and when I’m trying to keep up with the flow of traffic (75+ mph), it runs at 3,000 rpm or higher. This seems like the engine runs pretty high, and I always feel the need to shift up (I can’t obviously). Why is this? Other cars don’t seem to run this high of rpm. It also seems that the car isn’t really “relaxed” when cruising, and its seems like it would kill my gas milage. Is this a common practice in the automotive world of transmissions?


#2

Honda’s traditionally have small engines that have poor low RPM power. A way around this is to have very short gearing. The downside of this that at higher speeds the engines will turn higher RPM than say a V8 powered Corvette with much taller gearing that loafs around at 1400 RPM at 70 MPH.

You’re not hurting anything, the car was designed that way. The problem with using lower gearing in cars without a lot of power is that the car will struggle to maintain speed on almost any incline and will be less responsive since the engine won’t be operating in it’s power band.


#3

This is perfectly normal for a littl4 4 cyl engine. It isn’t harmful. The fuel economy could be marginally improved with another gear - and some cars are now coming with a “6th” gear. But what you get is what it is supposed to be.


#4

Agree; my wife leaves her car (Nissan Sentra)out of overdrive for most driving around the city. When she goes to the mountains she keeps it out of overdrive on uphill stretches as well,since going uphill, even gradually, puts these small 4 bangers at a real disdvantage.


#5

Honda engines run best about 1/2 way from idle (600 rpm) to red line (6,000 rpm). Anywhere in the 2,000 - 4,000 rpm range should be OK. If you approach a hill and it drops to 2,000 rpm, downshift a gear. On the flats, it will run all day at 3,000 – 4,000 rpm to keep up with traffic.

Twoton


#6

Thanks! Out of my friend base, I’m pretty much the only one who has a little 4-cyl, and the only one with a standard transmission, thats why I wasn’t sure if this was common in cars.


#7

Thanks everyone! I really appreciate all of your responses. While its on my mind, When I’m cruising down the road at, say 40 mph, should I keep it in 4th (the engine turns around 2,000 rpm)? or should I upshift to 5th? Keep in mind, I want the best economy. I ask this because in 4th at this speed, the engine feels “happy” sometimes if I upshift to early, or get into a really high gear, the engine turns nice and slow, but it sometimes feels like the engine is struggling, and its just not as “happy.” What would be best for gas milage?


#8

Well, I don’t know what you interpret as happy or not, but as a general rule best fuel economy will be achieved in the highest gear you can get without lugging the engine (where it starts to bog or stutter). This works ok for flat terrain but in hilly areas you’ll be shifting a lot. I think you should also consider the question of whether or not you’re over thinking it all. Something like the 4th/5th question on the whole is not going to make any huge difference in fuel economy unless maybe you’re talking about a really long trip at reasonably constant speeds.


#9

“The problem with using lower gearing in cars without a lot of power is that the car will struggle to maintain speed on almost any incline and will be less responsive since the engine won’t be operating in it’s power band.”

the opposite of this is true. With a higher gear, the engine will struggle to maintain speed on an incline. This is why I drive V6s or V8s.


#10

Well if I’m cruising down a regular street at 40 in 4th, by “happy” I mean, the car accelerates smoothly, without it grumbling, and the car feels much peppier. If I opt to shift into 5th, acceleration is not so smooth, and I have to push the gas down much farther to accelerate, but it never bogs down or stutters as long as I’m moving. Heck, I can drop it into 5th going 25 mph if I wanted, and the engine’ll still won’t stutter (as long as I don’t accelerate much).


#11

The “grumbling” means that you should just downshift.


#12

Lower gear = numerically higher higher gear. For example a 3.55 is a lower or shorter gear than a 2.73 or 3.08 axle ratio. Likewise a taller or higher gear is a numerically lower number.

The OP’s Honda likely has 4.xx axle rato. It’s a very short or lower ratio. If the OP’s Honda has a 2.76 axle ratio it would struggle mightily at climbing a grade since such a ratio would put the engine in a lower-than-optimal RPM.


#13

Isn’t that what I said?


#14

Ah yes, I got the terminology mixed up. I should’ve said

“The problem with using taller gearing in cars without a lot of power is that the car will struggle to maintain speed on almost any incline and will be less responsive since the engine won’t be operating in it’s power band.”

My mistake.


#15

I get confused with “taller” or “shorter” gears but I understand well “lower” and “higher” gears.
I would like to add; I had a new '66 Dodge station wagon with a 383 engine and 276:1 rear axle and that thing could run 90 mph easily in 2nd gear. But it had a hard time going up Pikes Peak. {or coming down).


#16

When you consider that Honda makes more units per year of internal combustion engines than any other brand ( by a huge margine, OBs, gens,Lawn mowers etc,), you can trust what the are trying to do. I don’t remember a motor manufacturer making a motor capable of 100 hp per liter w/o “charging” and made available in a compact before Honda. Besides, their red lines are still often well above any safe cruising speed.

All this HP doesn’t come free in a small motor and higher revs are the key. Just ask anyone who has driven a Honda for hundreds of thousands of trouble free miles. Besides, the higher RPM whine is necessary in some Hondas to hide the road noise. The newer Hondas are more “relaxed” though, for increased mpg with higher ratios.

BTW, don’t be an rpm watcher, been their and it drives you crazy. Just drive and enjoy.