Ralleh

The reason is that I rev the F out of the car whenever I get the chance and the top is always down (no hurricanes around here). I'm OK with that. I'm just wondering, as a thought exercise, if someone could change 6th gear to where you could get 35mpg highway or so. Like if someone spent a lot of time cruising on the highway and wanted better range. I'm not entirely sure if that means adding or subtracting teeth, since larger rear cogs on a bike cassette mean more rpms of pedaling, but larger front chainrings mean fewer rpms, so I dunno which applies to an engine transmission.

bluAP1s2k

Ralleh, I think you are on one track with the engine speed, but you must also consider that there are other factors that would directly affect gas mileage. Such as, Tire pressure, cleanliness of air/fuel filters or even the cleanliness of the fuel injectors.

starchland

for me obtaining 31 mpg easily without trying in a sports car is quite an impressive feat. I couldnt, however imagine cruising in 6th at 60 mph with any lower rpm. it wouldnt be enjoyable.

drewmob

alright, chief. i think you missed the point. did you look on s2ki or actually surf the interwebz???

unless there are a few engineers that have a lot of time to kill i'll give you the quick and dirty as best i can:

there are tons of factors that go into a final factory mpg rating for a car. IIRC its a calculation of mean engine load/efficiency based on weight v revs, or something along those lines. IE, you can gain highway mpgs but lose in-town mpgs or vice versa by adjusting the FD/gearing and matching to the tq curve... this is also the reason that alternative means of fuel savings (aero, shutting off cylinders, etc) is where a lot of r&d $ is at...

i think most people here would argue that your title is flawed. RPMs are why are cars *are* efficient.

if you really want an answer you should go do some research on the engineering factors that effect mpgs and apply those principals to what you know about the s2k.

btw, i know for a fact there are a few well thought-out threads on this subject around here somewhere. it would probably take time and effort to find them though...

iDomN8U

This car is a track car, imagine a very tall 6th gear when you're on the long straight on the track.

Ralleh

Yeah, what I'm talking about is not for a track car, just for someone like rob who wants to still look like James Bond in an s2k while he's running from the feds, but needs better range. If you're cruising on the highway though at a fixed speed, you're not having any fun anyway, so it doesn't matter if you're in the right position to take quick advantage of the power band. What I'm envisioning is a low revving 6th gear that feels like a Corolla or other POS when you punch it, but turns back into an s2k when you downshift to 5th.

Seems to me like Honda has the gearing revving the engine higher in the top gear so you have access to power in that gear, but if you want access to range instead, it should be possible to only change that one gear, instead of, say, lowering the gear ration of the final drive or something that would destroy the rest of the gears.

S2kRally

my 03 gets 28 mpg according to my calculations ... mostly highway all top up.

thats over the epa 27 mpg highway rating...

good enough for me

iDomN8U

There's a kit you can add to the car, kinda looks like this:



get's infinite mpg, only requires some nuts

cenix

i get over 30 miles per gallon on straight stretches of freeway at around 70 mph all day.

quite frankly, i think the rpm's is WHY our cars are efficient. we get great gas mileage if need be by cruising down low, and adequate power up top as well.

vader1

I have a supercharger, had been flooring it routinely since I installed it and still never got below 20mpg on a tank. Before the SC, my average tank was 25-27 MPG every time. Now I am getting about 24 but the car MOVES.