The Civic has a shift indicator, which I've never had in a car of mine before. I don't always follow it because it says to shift pretty early and feels underpowered. However when I'm in traffic or a flat road I usually shift when it tells me to. Sometimes it will have me up to a high gear at relatively low speeds (5th gear at as low as 30mph). The lowest the tachometer shows is 1000 rpm or so.

My dad says that would be bad for the car. He doesn't know much about cars though so I'm asking the Garage. I figure if I'm following the shift indicator it should be okay? Could high gear/low speed hurt the engine or transmission at all?

thanks

6/10/2006 9:27:35 PM

Shift when you think you need too. Sometimes I shift really early and others I like shifting later, of course I don't have a shift indicator.

6/10/2006 9:39:14 PM

its done based on engine vacuume they don't really work well.

6/10/2006 10:04:53 PM

so what, is that like GM skipshift?

6/10/2006 10:59:56 PM

no its a light

6/10/2006 11:20:58 PM

thats cuz there is too much powR

6/10/2006 11:28:51 PM

The Saturn I used to have had a shift up indicator. Whenever I shifted into 4th, it would immediately tell me to go ahead and shift into 5th. So yeah, I never listened to it and kept my rpm's high

6/10/2006 11:31:46 PM

my shift indicator comes on at 6900 rpms

6/10/2006 11:34:20 PM

Shift when it feels right.

6/10/2006 11:38:47 PM

i generally shift between 3-4k

6/10/2006 11:39:50 PM

i'm not sure about hondas but maybe try pushing the trip computer stalk 3 times and it might let you adjust the shift light indicator. that's how mine was adjusted on my g35

6/11/2006 12:00:39 AM

it senses a 4inch tin can muffler which addes 30+hp

6/11/2006 1:02:55 AM

theres no reason on earth a honda should ever be at below 2k besides when starting out. my car rarely sees below 2.5k. its the least efficient rangs for the motor so unless youre going downhill its not optimal for anything.

6/11/2006 6:51:06 AM

the redline is at 6k

will shifting later/earlier affect my gas milage at all?

6/11/2006 8:34:53 AM

Shift at the torque peak........Should net the best mileage

6/11/2006 9:00:31 AM

I've driven a few vehicles with shift indicators and they always light up too early. with a 4 cyl, you need to wind it up or you won't get any power. I have a little 4cyl ranger that I never shift below about 3000 and most of the time a lot higher than that. you just need to try different rpms and you'll find where the best shift point is. if you're going to accelerate to highway speed, you'll probably want to shift at a higher rpm than just easing around town.

6/11/2006 10:35:04 AM

I shifted witht he shift indicator one time in my saturn and I actually got pretty good gas mileage. It would usually have me shift into 5th around 33-35mph which would bring the revs down to 1800 or so. It's great to follow if you're a newer driver, but as you become more advanced just don't pay attention to it.

6/11/2006 2:08:18 PM

1.6 sohc non-vtec.... I don't think you need to be in 5th at 30.

You should probably shift at 3-4k rpm.

6/11/2006 2:57:51 PM

On my girly mustang:

first gear : 20 mph
second gear: 25 mph
third gear: 38mph
fourth gear: 45 mph
fifth gear: 45mph-110mph

6/11/2006 3:04:09 PM

Quote :

"I shifted witht he shift indicator one time in my saturn and I actually got pretty good gas mileage. It would usually have me shift into 5th around 33-35mph which would bring the revs down to 1800 or so. It's great to follow if you're a newer driver, but as you become more advanced just don't pay attention to it."

The Saturn's indicator is WAY off most of the time. Shifting into 5th below about 40-45 is retarded.

6/11/2006 3:35:43 PM

^^ so?

that doesn't really address her question at all. i'd imagine your mustang has more torque than her little 1.6L honda. it'd be easier for your car to pull the taller gear up to speed. i'm suprised her putting that car into 5th at 30 mph doesn't make it lull like a bitch, if not nearly stall out.

[Edited on June 11, 2006 at 4:49 PM. Reason : asdf]

6/11/2006 4:46:27 PM

of course if you shift really early you're gonna save gas. If you shift before 2k rpms you're gonna get alot more gas mileage but no power.

Think about it, if you're easy on the gas and shift early, you're fuel is comin out at 1/4 the rate at 1.5k rpms than it would at 6k. I'm not tryin to say you'll get 4x the fuel efficiency no, but you're gonna get better gas mileage for sure.

6/11/2006 8:46:56 PM

unless your engine knocks...in that case you reduce your mileage as well as engine life.

6/11/2006 8:49:34 PM

but it depends how the car responds to being so low in the rev range. for a 1.6L sohc honda engine there's no way 1k revs is in the optimal range. it's not efficient for the engine at that point. it's one thing to have low revs cruising at highway speed (a la a 6-spd corvette or bmw) but totally different to try and continue acceleration in 5th gear at 1k revs with a ~90 hp engine.

6/11/2006 8:51:59 PM

If you shift early, you'll get better gas mileage. If you shift later, you'll have better acceleration.

As long as you avoid the extremes (the engine isn't lugging and you're not spending a lot of time near redline) I wouldn't worry too much.

6/11/2006 8:54:22 PM

Big deal is to NOT "lug" the engine. I bet you've noticed that, if you shift too early, and especially if you shift early and give it a lot of gas, the car seems to vibrate a lot. This is something you DON'T want. Lugging puts undue strain on the engine's rod and main bearings; it is effectively hammering on them. The results? A bottom end that doesn't last like it should.

My recommendations for the Hondas? Shift between 2500 and 2750 rpm. The engine actually has a decent amount of torque and can pull the car up to speed. You don't want your rpms in the gear you're shifting into below around 1700 to 2000 rpm. Shifting at anything above 3000 rpm is just wasting fuel. Sure you get better acceleration, but your fuel economy suffers as a result.

You're an engineering student...you know about the trade-offs.

6/11/2006 10:34:56 PM

who gives a fuck about fuel economy

6/11/2006 10:47:25 PM

Don't know about you...

But I do.

Evidently, Nerdchick does too.

I ain't a high-rollin' baller with a bottomless bank account.

6/11/2006 11:10:05 PM

my honda shift light comes on at 15.5k

6/12/2006 4:53:09 AM

Quote :

"Think about it, if you're easy on the gas and shift early, you're fuel is comin out at 1/4 the rate at 1.5k rpms than it would at 6k."

not exactly true. the gas doesnt come out at a constant rate per RPM. the fuel injectors operate on a PWM signal and so have a certain duty cycle from like 10-100%.

so a 50% duty cycle (cruising maybe) at 3krpm is the same as 100% duty cycle (im bogging, need to floor it to get moving) at 1.5krpm

6/12/2006 8:41:16 AM

it's going to depend on the fuel maps in the ECU, which are not always designed for best gas mileage

6/12/2006 10:13:59 AM

gg jbaz

my wrangler has a shift indicator

i just laugh at it

6/12/2006 10:31:53 AM

yeah when I shift according to the light the acceleration sucks

but that's not a big concern for me in my commute, which has lots of traffic and I rarely get above 40mph

I haven't noticed any noises or vibration from the engine when going slow in a high gear, does that mean I'm OK? I just found the owners manual and it says to shift to 4th at 35mph, 5th at 48mph. It doesn't say much about the light, just that you should shift when it lights up. So which one do I obey for best engine life? The light or the rpms

6/12/2006 4:02:19 PM

The revs. Fuck the light.

6/12/2006 4:06:18 PM

my car never goes over 2.5k rpms

is that good?

6/12/2006 4:06:52 PM

i just idle everywhere i go in first.

6/12/2006 4:13:40 PM

^ powR

... but yeah, if I was going 30mph in 5th my car would almost stall Plus, it's REALLY bad to floor turbo'd cars at low RPMs.

[Edited on June 12, 2006 at 4:20 PM. Reason : low rpm + turbo + gas = boom]

6/12/2006 4:15:23 PM

I sometimes drive my car on 30 on the 5th...it just has poor pickup.

6/12/2006 4:15:57 PM

shift it where it feels right and don't worry about it. different situations require different shift points. you won't mess up the engine unless you really over-rev it.

6/13/2006 3:34:56 PM

here are the fuel maps for your car i believe. I think you have the VX PO7ecu anyways...



the numbers indicate time in msec the injectors are open for fuel maps
total timing in degrees for the ignition maps

for highway constant speed travel, learn the rpm which you will be at most, and you(I or someone) can lean out the map for that rpm/map and get excellent milage on the highway





[Edited on June 13, 2006 at 8:41 PM. Reason : numbers]

6/13/2006 8:32:56 PM

^tryin hard to impress someone?

6/18/2006 11:11:09 AM

^^ ok so is that fuel map have MAP on the left side (the rows) and then injector pulse width on the top (the columns)?

6/18/2006 4:32:39 PM

not tryin to impress... just a topic i know something about


rpm rows... map columns

pulse are the crossing of rpm X map

6/18/2006 5:25:17 PM

I can't wait until I get my megasquirt. Once I get it running I can datalog my pulsewidths... I could probably get like 25mpg on this bitch if I can tune the VE tables right

6/18/2006 11:37:22 PM

Quote :

"Shift when it feels right."

for some reason, this sounds like common sense

yet it applies so well

go figure

6/19/2006 4:12:06 AM

How do you know if your car has a shift indicator?

6/19/2006 1:18:47 PM

shift indicators are worthless.

I still call BS on 52 miles per gallon. maybe going 50 mph in 5th downhill.

6/19/2006 1:34:42 PM

Oh, well I just shift when it feels right. When I learned on my Mustang I fucked that thing up pretty bad. Well, not really. But man did it take me a while to getthe hang of things. I love how smoothly the BMW shifts though, and I usually shift around 2000-2700 RPM. When I'm in a hurry, or pissed at someone because they're driving like an asshat, I let it go up to 6000, though, and the engine sounds so nice and...jet-engine like. It's weird, when I would do that in the Eclipse, it sounded kind of electronic, but in the BMW it sounds really..different.

6/19/2006 1:39:01 PM

ben94gt told me mustangs are better than bmws.

6/19/2006 1:43:42 PM

*shrugs* it didn't shift as smoothly. I'm very happy with what I have now, but I miss the Mustang on occasion when it's sunny out - it was a convertible.

6/19/2006 1:44:56 PM