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If I am at 6000 rpms in 1st gear, am i using the same, more or less gas than 6000 rpms in 5th gear? I know the revs are the same but isnt the engine doing less work in 5th? so its more efficient?
 

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Waaaaaay more gas at 6000 rpm in 5th. It takes a lot of power to keep your car going that fast, while sustaining 6000 rpm in first gear doesn't.
 

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Keeping the engine at 6 grand in 5th requires the throttle to be open more than when its at 6000 in first right? Becuase as long as you dont move the pedal and therfore the accelertor pump the engine can only take in a certian amount of gas no matter what the load is on the engine. But if the throttle is open the same amount to get the engine at the same speed in 1st and 5th i can't see why it would use more gas.

-Aaron
 

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But if the throttle is open the same amount to get the engine at the same speed in 1st and 5th i can't see why it would use more gas.
If you're in 5th at 6000 rpm you'll be well in excess of 100mph, which will require a hell of a lot more fuel and throttle opening than whatever speed you'll be running in 1st.
For an example, stick your hand out the window at say, 35mph--then stick it out there at 135, see the difference? No, probably because you ran out of gas before you reached 135 with todays prices!!
At elevated speeds it has more to do with drag than just the rpm the engine is turning.
 

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All these mathematics questions are makin my brain hurt :eek:
 

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I'm going to sound like an idiot here. So at 6k in 1st the throttle must be open X amount. And to have the engine at 6k in 5th the throttle must be opened Y amount. In this instance Y will be greater than X right? In 5th there is more drag and therefore the engine must take in more gas and air to overcome the drag and still be at 6000 rpm so the throttle has to be open more. Correct?

BUT, gas usage is directly related to how much the throttle is open right? So if you had the throttle open X amount at 6k and then went into 5th and kept the throttle open the same amount you'd be using the same amount of gas but the rpm would drop since the extra load right?

I think for best milage you'd want to rev out each gear a little so that after you shift and press the gas pedal again, the engine isn't lugged or given too much gas where it just goes in and is burned half way. Becuase starting out from a stop in 4th or 5th gear usually just kills the motor or luggs it badly, and even if you give it lots of gas it wont really help because all the gas going in is just kinda flooding it and causing a bad air/fuel ratio. Same way with my stock 6 cylinder, if i floor it and kinda feather the throttle on the floor to use the accel pump to shoot more gas in it really doesnt help much, the one barrel can only take in so much air and the extra gas is just going along for the ride to be poorly burned and thrown out the exhuast. So for best milage (and probably performance) try to always have a good or perfect air/fuel ratio. That way there is never any wasted gas.

Well i dont kno if any of that made sense and alot of what i said is either wrong or everyone knows it already but oh well. I felt like typing.

-Aaron
 

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gas usage is directly related to how much the throttle is open right?
No.
Several years ago(the first gas crunch)BMW had a car with real tall gears to keep the rpm down, and they found if you drove the car with BIG throttle openings, but kept the rpm low, it got much better mileage than if you drove it with small throttle openings.
A carb will(to a point) only pull as much fuel as it needs, depending on how strong the signal is at the venturi, which will vary with the size of the throttle opening--Wide open with weak signal(low rpm), not much fuel pulled--part throttle with strong signal(higher rpm)more fuel pulled.

I think...what did I say? Who is this? Is this thing on?....................Oh never mind.
 

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Scooter said:
I'm going to sound like an idiot here.
Noooooooooooooooooooooo you didn't:rolleyes: . I don't think at 6000 RPM's you'll be saving fuel in any gear!:eek:

I think...what did I say? Who is this? Is this thing on?....................Oh never mind.
Did I say that out loud?:eek: ;) :D
 
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