My friends's sister has a 2000 TL and she says that she always uses the SS to change gears when/if the RPM reaches about 2000-2200. She keeps blabbing how it saves her a lot of gas, and she doesn't really care about the performance aspect. Could this be true? Does this save a lot of gas? could there be any consequences for changing gears this quickly?

 

That sounds like a low RPM. The engine actually would burn MORE gas if you shifted too soon.

It would be working harder.

 

I do the same thing occasionally, especially in traffic. it saves a 'reasonable' amount of gas I'd say. the shift computer allows it so I figure its fine. furthermore, it transitions pretty smoothly .. not harsh, so I'd say its fine until someone proves to me otherwise.

 

huh? how would it be working harder at 'lower rpms' ? its no different from driving a regular stick shift. once you find the earliest point where u can upshift without feeling the car jerk, then thats the most fuel efficient shift. the only issue is that there might be some issues with the SS. but hey, the computer allows it. . otherwise, it ignores u when you do it too early.

 

The engineering studies I have seen say that for modern fuel injection cars with precise fuel metering, the "egg on the gas pedal" school of thought actually raises fuel consumption. The cars do better by getting up to max fuel economy speed with crisp accleration (maybe half throttle or so). 45 mph is max fuel economy speed balancing efficiency of engine vs. aero drag. That is pretty umch the same for all cars these days.

 

hrrm.. interesting thought.. kinda like the question, if you're walking in rain. do you run and get more against you? or do you walk but spend more time in it to get more rain on you.

 

Think of it this way..I'm not a physicist but pretend you're riding your bike real slowly and then put it in top gear. How much harder do you have to pedal to keep up the pace? I assume that your engine does the same thing if you are in too low of a gear for that speed. Again, this should really only apply in a manual transmission since the transmission computer will avoid this even in SS mode.



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95 Integra GS-R Stock

2002 TL-S Aegean blue

 

The ECU won't allow you to upshift if the next higher gear would cause the engine to lug. If you have a 2000+... pop it in SS and try to shift into 5th at 35MPH and you'll see what I mean.

Also... I was always under the impression that a car was operating most efficiently (i.e. best MPG) at the lowest speed possible to lockup the torque converter 100% in the highest gear. For my 2000 that would be ~53MPH. Any thoughts?

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2000 WDP 3.2TL non-NAV
AEM CAI