i'm pretty sure there is already a thread about this somewhere, but we all know how crappy the search button is. so i thought i would make a (new) one.

okay someone said that if you stay in too low of an rpm it damages the engine over time. i tried finding it, and who said it, i can't seem to find it. so i figured we could talk about where we shift rpm wise and see what everybody thinks.

EDIT: found the thread https://www.cobaltss.net/forums/2-0l-lnf-performance-tech-153/high-gear-low-rpm-bucking-225838/

this is my normal driving
1st: 3,000
2nd:2,500
3rd:2,300
4th:2,000
5th: so 5th is my Overdrive and i cruise around 1,600-1,800 when i'm not on the highway
(i stay around 1,600-2,000)



and this is my driving for the past couple of days, since someone said it could damage your engine
1st: around 3,500
2nd:3,000
3rd2,500
4th: depends on the speed, but usually when i get around 2,300 i shift
(i stay around 2,000-2,5000)

now i'm in no way getting on it below 2k. i usually down shift if i'm at 2k or below, but after 2.5k i usually stay in the gear and pass.
let me know what your numbers are and get some feedback

 

lol how is shifting in low RPM gonna damage your engine? someone is feeding you nonesense... if that was the case GM wouldn't allow the car to shift at low RPM's... think about it? how on earth does a low RPM shift hurt the motor when it cruises at low RPM all day? it's not a high octane engine that carbons up at stop lights if you don't rev it... people will believe anything these days... helping the transmission or clutch... MAYBE.. but your engine? come on...

I cruise at 2k on the highway..

 

4k all day

 

thats what i said, i didn't think it would hurt, but just trying to get a response.
how fast do you go on the highway? lol my cruise is between 2.5k and 3k

oh boy

 

i shift in the city around 2500-3000 and on the highway cruise around 3000

 

Here's a a pretty good explanation:

http://www.subaruforester.org/vbulle...179-post6.html

Basically you don't want to put the engine UNDER LOAD with LOW RPMS because of the stress it places on the engine (rod bearings and crankshaft). Flooring it up a hill at 2000RPMS in 5th gear falls in this category.

 

shift around 2500rpms every gear. cruise around that on the highway too in 5th...

 

hmmm interesting

 

usually cruise around at 2k on the highway doing roughly 100km h sometimes in town around 1600 but i don`t put a load on the engine .. if i want to go faster i just downshift..

 

I think he's wrong on a few things
1: Fuel Air Mixture does not EXPLODE, It Burns.
2: When/if It DOES Explode, thats detonation ie: Running too low octane gasoline.
3: The burning process is timed to take the same ammount of time for the piston to get from the ignition timing point to TDC. Momentom does not overcome that pressure, beucase it isnt there yet, however it is overcomming the pressure of the compression.

4: From 32Degrees BTDC to TDC there isnt a whole lot of poston movment anyway.

5: And if becuse of heavy load on the engine the compustion process finishes before TDC, then the computer will pull timing and retard it. and show it on our interceptors as Knock Retard.

 

what? those are totally true, think about it.

 

Lugging is bad.

 

I think the post your talking about is about clutch wear...There was a post explaining how your clutch will slip if u shift below 3k alot..i always go...

1st 3k
2nd 3k
3rd 3k
Mostly skip 4th...nut if not 3k
and 5th 3k

 

Knock Control alleviates a lot of the issues that lugging used to cause. You're fine at whatever RPM you want, so long as she makes power.

 

I used to shift at 2.5K all the time, but I find it lugs and doesnt shift as smoothly.

1--2 =3-3.5K
2--3 =3K
3--4 =3K
4--5 =3-4K (varies)

 

I shift at about 3000 all day unless im feeling overly complacent

 

1st gear 6.5k then power shift to 2nd take it all the way to 7k slam it into 3rd

this is my normal driving

nah 1st- 3-4k depending on if i need to get some more go
2nd- 3k
3rd about 3k
4th 3k
5th when im going about 65, if the freeway has a slight hill ill leave it in 4th so i dont stress the car if im at too low of a rpm

and i down shift and rev match when i have to drop a gear, pop snap crackle

 

Which brings me to my next question. Is it bad to slowly let out your clutch when downshifting and braking vice rev matching? IE letting the clutch match the revs

 

i shift at 4k in 6th.

 

Normal Driving
1st 2.5k
2nd 2k
3rd 3k
4th skip
5th 2k

Skip 4th because it is so close to 5th, why shift and extra gear for only a few hundred rpm at 45-50mph. 5th will net better fuel economy if you are cruising (not accelerating or slowing down) and your engine will last longer running at a lower rpm.

 

Depends on your Rpm's...if its over like 2k then learn how to heel-toe. The cobalt has that mechanism where it hangs the idle high while rolling so that you can just let the clutch out in a somewhat quick manner, without rev-matching, however this is assuming you use the right gear for the speed your going. If your getting off the highway and your going from 5th to 3rd and your trying to let the clutch out slow before the exit ramp then your clutch wont last long. My friend has an evo IX which now has almost 90k on it. It had its transmission rebuilt and clutch replaced at about 78k. We didnt know the tranny needed a rebuild, we just experienced some extreme slip. He got the car with....i believe 60k on it? However the point is that he does your method of using the clutch to let it out slow in order to make a downshift smooth is just wearing out your clutch x fold more than it needs to be. If you learn to rev match your clutch will last much longer!

 

so like when u come up to a turn and u dont rev match it, but hold the clutch to downshift and let it out at a certain rpm so that its smooth?

i do that when i dont want to downshift and rev match sometimes

ex: going 45mph my street is coming up and i have to turn left

im in 4th so ill brake and when i get to a reasonable mph for 2nd ill drop it through the gears but not let go of the clutch and once in 2nd give it some gas to be smooth and its fine

i think that dont rev match and downshift do it this way generally

 

Its more like im coming to a stop and i just slowly start to let out the clutch then the revs just match up as im lettin it out.

 

ok i gotcha, yea just blip the throttle and get off the clutch as fast a possible

if u dont need to be on the clutch get off it so u dont cause unneeded wear

i mean there are times were u cant do it so just let the car coast in the gear till u can properly drop gear

i learned how to drive stick on my cobalt(as my onw car, i drive a tractor truck at work hahaha monster clutch) and i realized rev matching and downshift is a better method

 

yeah when Im downshifting Ill blip the throttle about 1500 higher (assuming im dropping one gear down) and Ill pretend like Im upshifting and its usually seamless.

I never let the clutch match the RPMS, hell I feel bad riding the clutch at a drivethrough at 500ish rpm not moving let alone being at 3kRPM and slipping it