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powerslave
02-02-2004, 09:41 PM
What would you considered to be the optimum RPM range for everyday driving? For example when you are just coasting at a higher speed, do you upshift to the top gear where your tach is at say 1500 (where it takes forever to speed up) or do you keep it a little higher in the second highest gear at around 2500-3000?

Are there any bad effects of driving at too low of an RPM? Reason I'm asking is that my dad, who drives an Accord drives at a really low RPM. He's noticed the car shakes (sometimes quite a bit during the colder days). He takes good care of the car and has had most of the vital things replaced and the car still shakes.

1badPT
02-02-2004, 10:05 PM
Well too low would be stalling. As long as that's not happening, the worst thing that is going to happen is you'll gunk up the engine with carbon deposits and varnishes.

Its hard to say what RPM is ideal because it will be different for each engine, but for my car, redline is just over 6000, and I usually try to keep it between 2000-4500, except when cruising, then its just under 2000 (and the engine goes silent :) )

To sum up, if its shaking, step on the big pedal :tongue: or downshift :D

hampstor
02-02-2004, 10:15 PM
if i'm driving around, the engine feels great at 2000-2500rpm... then again my car sucks an incredible amount of gas for a 4cyl so I don't like to rev it high if i can help it :)

EK 2.0
02-02-2004, 10:15 PM
Like PT said...different for all cars/trucks...listen to your engine, and feel for its vibrations...it will tell you where it likes to be...

powerslave
02-02-2004, 10:32 PM
Originally posted by 1badPT
Well too low would be stalling. As long as that's not happening, the worst thing that is going to happen is you'll gunk up the engine with carbon deposits and varnishes.


Could this potentially be the reason his car is shaking? Should I urge him to do the old "Italian tune-up"? :)
I can just imagine his reaction, don't think he's ever taken the car over 4000.

Akagi Redsuns
02-02-2004, 11:27 PM
You should be at a RPM where the engine is neither racing or bogging. Bogging an engine is not good for it either. More stress on the pistons, crankshaft and bearings as the force of combustion is not translated down to the crankshaft because of resistance of the road to the half-shafts, then differentional, transmission, flywheel...crankshaft.

Luigi
02-02-2004, 11:38 PM
i know if i bog my engine the car starts to shake so i just downshift to get the revs up, smoothes the car right out.

Wildcat
02-02-2004, 11:45 PM
alot of cars dont even have an rpm gauge, its all driver listening to his car. i havent looked at my rpm levels since i was 16 :)

dj_rice
02-03-2004, 12:30 AM
Haha its like my dad drivin my car when he first bought it for me...

I have a redline of I think 6500 or 7000RPM..I drive a 93 Nissan 240sx but he kept tellin me I was shifting at too high of a RPM which I was shifting around 2500 -3000rpm which when u listen to the engine is like optimum shifting range...he woudl shift at like 2000rpm

GTS Jeff
02-03-2004, 12:32 AM
dude, if your dad is driving around at rpms low enough to make the engine shake and struggle, he is hurtin the fuck out of it by placing a huge load on it. tell him that the best way to take care of an engine is to not make it shake.

Team_Mclaren
02-03-2004, 01:06 AM
Originally posted by GTS Jeff
dude, if your dad is driving around at rpms low enough to make the engine shake and struggle, he is hurtin the fuck out of it by placing a huge load on it. tell him that the best way to take care of an engine is to not make it shake.

thats what i thought, your puttin too much load on the motor, and no matter how hard u step on the gas it just wont go.... downshift, thats what the redline is for. thats i think under reving your engine

Ben
02-03-2004, 01:11 AM
Sounds like a few peoples fathers on this forum nead to learn how TF to drive a car. Lugging the car so it shakes is not healthy whatsoever.

Every car is different, Some cars have no bottom end and have a huge Peak to them (Most Hondas), others run out of steam around 5500RPM but have a nice low end torque curve.

Also depends on your Cam Profiles and such, My car for example has aftermarket camshafts which take away a bit of the lowend power and increase a huge amount in the top end, they kick in around 3500rpm's and pull to 7100, so I generally shift when driving around town in a regular manor at 32-3300rpm's, thats what sounds most natural for the car, and doesn't eat fuel as badly. I'm not racing the soccer moms or the school bus', no need to use more than half throttle. Other people I have driven with whom drive 'peakier' cars and have no power under 4000-4500rpm tend to rev their engines a lot higher because they have to. The car is just too damn slow off the line when keeping the rpm's low. City bus's are out accellerating them. Listen to the car and whats going on around you, the environment generally dictates when and how you should shift. Driving down McLeod Trail in second gear is pretty much pointless unless you're sitting in your engines powerband wanting to race or something :rolleyes:, but putting the car in 5th while rolling through a school zone is not practical either. 30km/h in my car is 2000rpm in second gear. Rule of thumb for my car is in every day driving I shouldn't have to downshift untill I reach 1800rpm's, some of you out there whom have no torque, will probably have to raise that up to 2500 or more even. This is of course only MY ideals, under normal city cruising, which I have found yields the optimum fuel economy for MY car, you're results will differ based on your driving style and car you drive.

Zero102
02-03-2004, 09:47 AM
I usually upshift at 3000-3200, but if I'm pushing it, I will shift at 4500-5000 sometimes.
As a rule, I never push the gas down more than 1/4 if it's under 2000rpm, or else it starts to lug.
Lugging is WAAY worse for the engine than revving it too high.
For any standard, I wouldn't shift before at least 2500.
But maybe I've driven too many 4-bangers.

hjr
02-03-2004, 10:31 AM
Originally posted by powerslave
What would you considered to be the optimum RPM range for everyday driving? For example when you are just coasting at a higher speed, do you upshift to the top gear where your tach is at say 1500 (where it takes forever to speed up) or do you keep it a little higher in the second highest gear at around 2500-3000?

Are there any bad effects of driving at too low of an RPM? Reason I'm asking is that my dad, who drives an Accord drives at a really low RPM. He's noticed the car shakes (sometimes quite a bit during the colder days). He takes good care of the car and has had most of the vital things replaced and the car still shakes. ya dude, tell you dad to put his foot down. gas gas gas. thats the solution. haha. 1500 rpm. thats rediculus. he's one of those dudes who cant get out of his own way i take it. do people honk at him a lot? maybe more than average occurances of obscene jestures coming his way? here is the answer, speed up!

Bonka
02-03-2004, 07:56 PM
Originally posted by hjr
ya dude, tell you dad to put his foot down. gas gas gas. thats the solution. haha. 1500 rpm. thats rediculus. he's one of those dudes who cant get out of his own way i take it. do people honk at him a lot? maybe more than average occurances of obscene jestures coming his way? here is the answer, speed up!

At 1,500rpms, my car's between 60-70km/h on a light foot :tongue:

Not sure what the problem is with the low rpms unless he's on the highway..

If he has an OD button, maybe he should turn that off. If he doesn't have an overdrive button, but he has a "2" or "3" gear selection on the stick, maybe want to use that instead of "D"..

Akagi Redsuns
02-04-2004, 12:57 AM
I think he has a manual as no automatic would bog an engine so bad to cause it to shudder. Automatics do a good job in keeping the engine in optimal RPM range.

biggie_82
02-05-2004, 09:49 PM
2000-3000 RPMs.