Is it better to have the RPM run a little low or a little high? (manual trans)?

Question

When I'm going 25 mph, 3rd gear is higher than 2,000RPM, while 4th gear makes it run about 1.5 rpm.. I have the same dilemma with 35mph.

Is it bad to have it run low (it isn't to the point where it is sputtering)?. Is it bad to have it run a little high? Is one more fuel efficient?

Answer 1

I would go with 3rd for 25MPH and I am guessing at 35MPH you have the same issue but with 4th and 5th gear, so I would again go with the lower gear and higher RPMs because that high of a gear at that low of a speed causes the motor to "lug" or work harder than it needs to, especially if you are going up a hill or trying to accelerate. Your motor will be happier and so will you. You owner's manual should even have some sort of guideline for this same question, provided you didn't throw it away or put it in the garage and lose it. Have fun with your vehicle!

Answer 2

Low rpm is definitely more fuel efficient. Engine friction and "pumping losses" increase very fast as rpm increases.

As long as the car doesn't jerk or run rough, low is better. But, other than gas mileage, it makes little difference.

Answer 3

I force a Camaro SS (LS1) and that i in user-friendly words use proper type. you should use decrease grades yet you'll conflict through in performance and in gas mileage. Plus the gas is dirtier with sediment, so it is going to bathroom down your engine over the years. the claener the gas=the added effective burn because the outcome of the gas wanting a decrease spark temp to ignitie. Zenas Walter (above placed up) would not recognize what he's speaking about. utilizing proper type will honestly enhance the existence of your engine. otherwise, whats the point. What an fool. My opinion, use your T/A as only a weekend warroir/cruiser. it is going to keep the mileage and the cost of gas down.

Answer 4

It would be better to run a little higher rpm than lower because that way you might not stall out as much and it will run cooler allso because the water pump will be pumping more coolant through the radiator.You should not notice any fuel economy difference.

Answer 5

you want to run in the higest gear possible without shuttering...or lowest rpm which is the same thing in other words

Answer 6

you must be referring to your idle rpm..........this has no factor at speeds above idle........set your idle rpm to manufacture,s specs.your engine rpm is supposed to be lower in higher gears! if your concerned about specific rpm@certain speeds.......lower will save gas as long as your not forcing the engine to labor....higher will seem to give more power but will cost you gas economy......lower-higher meaning rpm!

Answer 7

Do not red line.