Methods of shifting.
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Technically, piston motors operate at 100% efficiency at WOT. If you gave it everything you got, everywhere you go, you'll get better fuel economy. Lol, i swear to you that this is true. However, i shift at 4k rpms and VTEC every once ina while and i got 27mpg when i filled up last night
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From: Wilmington, DE
Originally Posted by RazorV3,Oct 5 2005, 02:19 PM
its all about throttle position. the more throttle you give, the more fuel is being fed through the injectors. the rpm can be really high at 8k rpm when you're engine braking, but you will be using no fuel because your foot would be off the throttle and the injectors are fully closed during engine braking/de-acceleration.
1- Stock engine (AP1 or AP2 will have different values)
2- Constant RPM excluding initial acceleration and final deceleration
3- Top up or down - i'm guessing we'll see different values.
I'm not suggesting someone spend their weekend at a track and do this, but I'm sure honda has performed smaller versions of these tests, and has extrapolated the results. The data gathered should come up with a 'sweet spot' for the engine to operate at. The point where speed/MPG is maximized.
To put my thoughts another way, is it better to run in 6th gear at 75mph (4000rpm) or at 55mph (no clue what that rpm is)? Of course the lower rpm will burn less gas, but will you go farther in the end (IE better gas mileage)? Will an S traveling at 75mph make it farther on one tank of gas then the guy doing 55mph?
Once we've figured out the optimal rpm range, than figuring out the shift points will be a matter of entering the sweet spot rpms, and staying there as long as possible.
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From: Bay Area
Something that's not mentioned yet: keep the top up to save gas. There is a huge difference between top-up and top-down in terms of wind resistance. Or better yet, get a hard top and keep it on (though it does add weight to the car unless you remove the soft top).
edit: And another thing: keep the car washed and waxed to save gas.
edit: And another thing: keep the car washed and waxed to save gas.
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Originally Posted by skier219,Oct 1 2005, 04:37 PM
For most of my driving, on crowded roads, I throttle gently and shift around 4000rpm. This gives me 27-29mpg on a regular basis (with a lot of highway mixed in).
Craig
Craig
are you guys really driving the s2000 or what?
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From: Bay Area
Originally Posted by RazorV3,Oct 5 2005, 11:19 AM
its all about throttle position. the more throttle you give, the more fuel is being fed through the injectors. the rpm can be really high at 8k rpm when you're engine braking, but you will be using no fuel because your foot would be off the throttle and the injectors are fully closed during engine braking/de-acceleration.
This is also one reason why BMW can get greater efficiency from Valvetronic engines, where the throttle is replaced by infinitely variable valve timing and lift. I believe Honda incorporated something similar into the new R series engine in the 2006 Civic. The aim of both of these systems is to improve efficiency at small throttle openings by reducing pumping losses. If you could do that, then what you said would be true.
Peter
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From: LittlecountrynamedBelgium
I did not have time to read all the other replies, sorry for that, but here is my impression...
1. You can shift as early as 2500rpm without a problem. In the next gear you will stay above 2000rpm and that is fine for the engine. The higher the revs, the more fuel/air goes into the engine every second;
2. As what I learned, it is more fuel efficient to reach your desired speed more quickly. Trying to reach 60 mph while accelerating very slowly will cost you more fuel then reaching it with a more heavy and short acceleration;
3. While decelerating, stay in the highest possible (above 2000 rpm) gear without being on the throttle and downshift (avoid money shifting
) for braking on the engine, in that case you will consume no fuel. Decelerating when in neutral will cost fuel since the engine will need fuel to keep turning;
4. Watch ahead and look for lights going red or traffic blocking the road and that sort of things. Braking is a waste of valuable energy!
I learned these lessons while driving my 2 litre 16v NA GTI for about 10 years which had a digital on board computer showing continuously the exact amount of fuel used. With these basic rules I consume about 8.5 litres of fuel with my S2000 on normal roads...
This being said, It is so f*cking nice to get the engine to boil at 9k and the adrenaline pumping trough your body
1. You can shift as early as 2500rpm without a problem. In the next gear you will stay above 2000rpm and that is fine for the engine. The higher the revs, the more fuel/air goes into the engine every second;
2. As what I learned, it is more fuel efficient to reach your desired speed more quickly. Trying to reach 60 mph while accelerating very slowly will cost you more fuel then reaching it with a more heavy and short acceleration;
3. While decelerating, stay in the highest possible (above 2000 rpm) gear without being on the throttle and downshift (avoid money shifting
) for braking on the engine, in that case you will consume no fuel. Decelerating when in neutral will cost fuel since the engine will need fuel to keep turning;4. Watch ahead and look for lights going red or traffic blocking the road and that sort of things. Braking is a waste of valuable energy!
I learned these lessons while driving my 2 litre 16v NA GTI for about 10 years which had a digital on board computer showing continuously the exact amount of fuel used. With these basic rules I consume about 8.5 litres of fuel with my S2000 on normal roads...
This being said, It is so f*cking nice to get the engine to boil at 9k and the adrenaline pumping trough your body
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From: Bay Area
Originally Posted by Lionheart,Oct 5 2005, 10:44 PM
3. While decelerating, stay in the highest possible (above 2000 rpm) gear without being on the throttle and downshift (avoid money shifting ) for braking on the engine, in that case you will consume no fuel. Decelerating when in neutral will cost fuel since the engine will need fuel to keep turning;
) for braking on the engine, in that case you will consume no fuel. Decelerating when in neutral will cost fuel since the engine will need fuel to keep turning;". What exactly is "money shifting"? It is a new term for me. Thanks. 