Hi,

I just got my RX about two weeks ago and I havent driven a manual car before. Now I got the whole shifting down (rarely do I stall the car), but I get really bad MPG (13 low, happened once, REALLY REALLY heavy traffic) and my high is 20ish (Freeway but with congestion, the 210 FW in CA around LA area is pretty bad). I was hoping I could raise it but I suppose I burn a lot of gas when I go from a stop. What is a good rpm to be at so I can move from a dead stop while not burning a gallon of gas everytime I stop?

 

Zero RPM to answer the title.

Uhm, I get 13-14mpg on EVERY tank and you'll find many others who will say the same.
And then you'll have those others who claim 18+.
I'm not sure what you are expecting?

 

0 rpm = ∞ mpg

your mileage is normal. this is not a prius or a civic.

just enjoy it

 

oooooo......I couldve sworn people were saying that they got around 24, that's why I was very surprised

 

can't divide by 0

 

24mpg in an rx, especially in the city? good luck with that

 

Thats inaccurate. You traverse 0 miles and use 0 gallons.

Equation would give 0/0 which is undefined.

It could be 0 since 0 divided by anything is 0.
It could be infinity since anything divided by 0 goes towards infinity.
It could be 1 since a number divided by itself is 1.

 

I get 24 MPG in the city at 9200 RPM.

 

i get about 10mpg, does that make u feel better?

 

basically it just depends on where you are driving (speed, conditions, etc). when i drove from wisconsin back to indy, i got about 23-24 mpg. when i drive to and from work, i get around 14-15 if i am lucky

 

Don't exceed 3k in any gear and of course use overdrive (6th gear) on the highway.

But the best way to get better fuel efficiency, in any vehicle, is to slow down. I can't bring myself to do it, but if you stay under 55 mph your mileage will increase dramatically.

However, if you're looking for consistently high gas mileage in the '8, you've decidedly chosen the wrong vehicle!

 

The lower the revs, the better your fuel economy, assuming the revs aren't so low that the car has difficulty maintaining your speed..

 

6th gear at 3000 or less and drive that way for long periods of time.

just depends on if you have city driving or hi-way driving how much you'll get.

but yea if you in congestion daily, you are doomed.

I definitely get more than 20+ but I am almost all high speed driving and very little stops. That includes messing around at least once daily.

 

Where X = RPM: Lim (X -> +0) [mpg function](X)

I think that should give you a proper answer. :P I think gearing might become another variable.

 

answer:

tow rope!

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24mpg is doable for pure highway driving... as in road trip! otherwise be happy if you get 15!

 

Not many real answers here... I get right at 19mpg almost every tank. I keep my rpm between 2000-3500 when I drive with a few spirited blasts here and there. I drive about half city and half hwy so my mpg is pretty reasonable. Also, our engine is cleaner and runs better when you rev it hard once or twice a day. And if youre getting crazy low mpgs it may be another problem, like a led foot, CEL, or bad plugs coils or wires.

 

Not exactly on topic, but maybe if you went with some really light weight rims you could increase you mileage a little. Although, it would take a lot of miles to offset the cost. A K&N might help as well. I've heard to maximize hwy mileage try to keep it below 3700 rpm as that is when the secondaries open.

 

thanks. i didnt know you couldnt divide by zero. that must be why i'm dropping my differential equations course.

 

L'Hospital ftw!

 

Oldragger has changed his G/box to an 09 which gives him a higher ratio 6th . IIRC His rpm at 70mph dropped from around 4000 to 3300(ish) and mileage improved 2-3mpg .

Thread answered

 

In a series I car, 4000 RPM in 6th is 80 MPH, not 70.
Interesting thing about the transmission swap. I thought the '09 transmission makes the engine rev even higher than the series I. Guess I was wrong
However, this would mean that the series II cars should consistently get better gas mileage than series I which is not the case as far as I know.

 

OK - my main point was that reduced cruise rpm DID make mpg better

series II has a higher diff ratio don't forget .....

 

also, anything that lowers the weight of the car will increase mileage

some weight reduction is possible, but expensive. light rims, light exhaust, carbon fiber parts, etc.

some is not practical. removing back seat, stuff like that.

some is dangerous. drafting behind rigs, doing a lot of coasting / loading, with plenty of idle time in between.

keeping a big distance in front of you helps with the coasting / loading thing instead of following close and braking/accellerating. but if CA is like MD, people will constantly squeeze in front of you unless you follow the car in front of you closely.

keep your air filter clean. use premium gas. i really dont like or recommend K&N clogmaster filters.

i'm getting about 20mpg hwy, sometimes 22.

ecomodder.com has lots of ideas. good luck.

 

Lest we forget that running around at super low rev's for the gear you are in can lead to far more expensive issues that bad gas mileage!

 

lowest gas mileage, 10mpg, all day autocross practice
highest gas mileage, all highway cruise at 77mph, 23mpg