tips on how to raise mpg?
04-10-05, 07:04 PM
#51
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Originally Posted by WAYNE88N/A
Man, if I had to drive most of the time in the city, stop n' go traffic, and crap like that, I'd get rid of the car, lol...
My rx8 gets 17.5-18 so far all city, so *meh*
07-29-05, 02:05 AM
#52
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Originally Posted by Snrub
Well you see, there's this thing called the internal combustion engine. 
One of the characteristics of it is that it is most efficient under a certain amount of load. (I'm not going to get into the 'whys') Efficiency is when something is able to perform a task by using the least amount of inputs. It's not a perfect relationship though and at a certain point it becomes less efficient. Driving at a constant speed of 35mph for a given distance will consume more fuel than traveling at 60mph over the same distance. Primary credit for this characteristic does not go to "flywheel effect" or momentum, the same applies with a conventional piston engine. Sorry for the sarcasm. 
One of the characteristics of it is that it is most efficient under a certain amount of load. (I'm not going to get into the 'whys') Efficiency is when something is able to perform a task by using the least amount of inputs. It's not a perfect relationship though and at a certain point it becomes less efficient. Driving at a constant speed of 35mph for a given distance will consume more fuel than traveling at 60mph over the same distance. Primary credit for this characteristic does not go to "flywheel effect" or momentum, the same applies with a conventional piston engine. Sorry for the sarcasm.
07-29-05, 06:35 AM
#53
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Originally Posted by dDuB
I still get 17.5 mpg so I'm happy
My rx8 gets 17.5-18 so far all city, so *meh*
My rx8 gets 17.5-18 so far all city, so *meh*
I've gotten *28* MPG driving almost all freeway.
That's a 400+ mile distance between gas fill-up's on a 16.6 gallon Zenki gas tank.
If you're happy with your 18mpg city, does this make me on cloud 9 with my 28mpg?
-Ted
07-29-05, 09:21 AM
#54
Originally Posted by locketine
I would wager (knows little about characteristics of flame fronts and other neato things in the combustion process) that our peak torque (about 3500 rpms) in 5th will be the best possible gas milleage. This is backed up by everything said here.
As near as I can tell, the closer I can run to 3500 RPM, the better the fuel economy. The trips when I'm cruising slower due to police presence (quota time), I get worse economy.
However, the 3500 RPM point may actually be an artificial limit due to the stock ECU. The S4 NA ECU, at least, goes out of closed loop mode at right around 3500 RPM. It also will end up dropping out of closed loop mode on most hills at that speed, just due to the manifold pressure requirements to maintain speed.
The real test of the engine would be to get a nicely tuned standalone & do the mileage calculation. From talking to people with tuned standalones (usually running in open loop mode at cruise, just tuned with a wideband, and usually a bit lean of stoich), fuel economy doesn't begin to drop significantly until somewhere over 100mph. The engine efficiency apparently rises more or less proportional to air drag until that point.
... I'd love to find a place to test this. Anyone know somewhere in the US I can run 100+ for miles on end without getting pulled over?
The other interesting question is, "What kind of fuel economy do other cars get at 85-100mph?" I know I can do a bit more for economy (get the injectors cleaned, get a standalone), but I'm still pulling 23-25mpg cruising at 80-85. What does a typical Honda or Toyota get at those speeds? Suddenly a '7 doesn't look *quite* as bad...
-=Russ=-
08-03-05, 12:58 PM
#55
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Originally Posted by Syonyk
What does a typical Honda or Toyota get at those speeds? Suddenly a '7 doesn't look *quite* as bad...
08-03-05, 01:01 PM
#56
Engine, Not Motor
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Originally Posted by Syonyk
The other interesting question is, "What kind of fuel economy do other cars get at 85-100mph?"
08-03-05, 02:33 PM
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Originally Posted by Aaron Cake
I'll keep that in mind the next time I drive 1000 miles on 10 gallons of gas...
and i guess if you believe in equilibrium or whatever, the Insight balances out the inefficiency and emissions of the 7, hehe...
08-03-05, 04:14 PM
#61
56mpg on my 1.6L non-turbo diesel jetta (1984) with a minor fuel leak - SUCKA - LOL
BTW - that was calculated at 130kms an hour on a trip to daytona beach for spring break last year
But bear in mind that that power plant only cranks out 52 bhp and 61ftlbs at the flywheel, so you damn well better get some good mileage!!
BTW - that was calculated at 130kms an hour on a trip to daytona beach for spring break last year
But bear in mind that that power plant only cranks out 52 bhp and 61ftlbs at the flywheel, so you damn well better get some good mileage!!
Last edited by classicauto; 08-03-05 at 04:18 PM. Reason: omissions
08-04-05, 06:15 AM
#62
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I drive 35 miles a day onFC3C n/a, 4 city, 31 hwy. Im reverse commute, so freeway is 75-100, top down on way home, paying 2.69 gallon, cant stand 3100 rpms, so about 15-18, but I dont work Fridays anymore, should improve there, so------who cares!!! I didnt buy my FC to drive like my mother. If I keep it where it is at, Im happy. I guess I could put in regular gas, yeah right. If I worried about mpg, I would have bought a tricycle.
Peace. RUF RUF RUF
Peace. RUF RUF RUF
