Nemesis8

iTrader: (3)

Has anyone checked their CANScan data to see what your MPG says while on crusie control? I did this morning, and here is what it read: 30.4MPG !

Is this right? I'm I really getting this fuel economy while at these conditions? The OBD says I am from the PCM data.

rx8wannahave

Hmmmm....I did hear that Polak got like 28mpg on a road trip if I remember correctly.

Gosh...maybe the RX8 is the perfect car??? LOL

zoom44

kevin after all this time you still dont believe teh mileage you can achieve with this car? i thought i had you convinced after our 7stock run?

G8rboy

I've always felt the CanSCAN mpg calculation to be overly optimistic... I'd imagine that that RPM in 6th, you'd be getting 25-26mpg at best (I've done several road trips on rural highways at about those speeds).

khtm

What speeds are you guys driving to get those MPG w/ cruise?

dmp

24mph, 6th gear - I90 from Seattle to Boston.

:D

khtm

hahahaha damn that must have been like 100 RPM :D

Nemesis8

iTrader: (3)

You must of been reading my mind... I looked at those gas receipts last night. Given our occassional spirited driving sessions thru the twisties, I had a 24.7MPG and a 23.8MPG tank in the trip.

Nemesis8

iTrader: (3)

6th Gear @ 67.7 MPH

zoom44

and i had 2 23.99 tanks in a row thats easily conceivable that you were geting 30.x during that time period. remeber that it is still an avg= perhaps it was really flat there or even down hill slightly. later when going up hill it would go down, take into account on and off ramp speeds etc and you get an avg for teh whole tank. you probably got somewhere around 24 total if it was all highway. right?

Nemesis8

iTrader: (3)

Correct, I was traveling on a flat part of the highway this morning, but I just had to post that "instantaneous MPG" reading because it said 30.4 :D

I have been averaging allot higher MPG figures combined city/highway lately. I think the car is breathing very well right now. Once I get the RB intake on and the N flash, I think it will improve once again. Then... when I lean out the AFR, I will be one happy camper! :p

RosscoP

What's CANScan? Forgive my ignorance! How do you get that data?
RosscoP

Howard

Cruise at 78 in 6th for 150 miles. 20 mpg

Peregrine8

I am wondering the same as RosscoP, I'd love for there to be some easy way to check my mileage.

Nemesis8

iTrader: (3)

It's hardware device with software that plugs into your OBD port under the dash.

http://www.ghg.net/dharrison/canscan.htm

Canzoomer sells a customized version if you are going to tune your AFR.

This MPG I noted was under 42% load on flat ground. Going downhill under no load it will be more, and going uphill under higher loads it will be less. But on flat ground I thought it was worth posting.

midlife crisis

On a recent 1200 mile trip I managed a tank at 21.3, another 20.8 and about 20 for the rest. About 75 mph, cruise on and air off.

G8rboy

It's a data scan device that hooks up to your OBDII port under the dash, and to a laptop to view the data. New cars like the RX8 have a CAN bus that provides a ton of real-time data from the PCM... much better than the older OBD static info. Some people have developed custom carputer apps that tap into the Navi screen for monitoring various things like this... if I ever get some free time I'm going to play with that as well.

Here's where I got mine- the guy that developed it has an RX8, so you know it's good : )

http://www.ghg.net/dharrison/canscan.htm

Jud

Ok, for over a year now I've wanted this car. But everytime I look into it, the gas mileage always throws me. And now, this thread. I have an automatic 99Cougar now and I get 28+mpg doing 70 with cruise control on. That's pretty close to the RX-8 numbers in this thread. So I don't want to sound like Grandpa here(I'm only 32), but if the one guy said he gets like 20mpg doing 75, how fast are you other people driving? Why don't you slow your a$$es down so I can justify buying this car to my wife!

Jud

G8rboy

Keep in mind EPA estimates for highway are 24mpg, and they are very optimistic. Doing 70mph with cruise on you're going to be real lucky to get even that. The Renesis has various ports and injectors that open at certain RPM and throttle points, so maximum fuel economy is going to come at 3500rpm or lower, which roughly 65mph or slower in 6th gear.... something that most of us won't do to save a few bucks. My slower highway trips are 21-23mpg (@65-70mph), but real interstate driving (85-95mph) is brings things down to 18-20mpg. If you really open it up and have some fun with it, keeping the revs up for passing people or just exercising the motor, the mileage goes down from there... but that's the point of the RX8 in my opinion.

That said, if you're looking for fuel economy, this is probably car #174 on the list of smart buys... but if you're looking for the best well rounded fun and sporty 4 seater, it's in the top 2 or 3.

LawFitz

Jud, the MPG on my car is almost as bad as my friends' Hemi Dodge Truck and Z71 Tahoe. If you're concerned about MPG, this is not the car for you.

14-16 MPG in 75/25 city/hwy normal (as in not hard) driving. On hwy only, I have been able to get about 18-19 MPG.

My car may be a lemon though. F me.

Caveat Emptor.

Old Rotor

I did 2 tanks with the cruise set at 75mph and got 24.5mpg. I have the A/T. This was on flat all hwy driving.

Nemesis8

iTrader: (3)

Also remember that the dashboard instruments are not reading the correct RPM or the correct MPH. My dash was reading 69 MPH and 3500 RPM, but the PCM was reading 67.7 MPH and 3374 RPM.

rx8wannahave

Jud I'll PM you about your question...since you got kind of a negative while semi-honest response.

Note: I think the people who replied to him were being honest I'm just saying it's semi-honest because not everyone is getting 13-16mpg in the city (I'm one of them) so I thought I'd say something to the poor guy...lol...all he wants is an RX8...lol

G8rboy

There's no reason to sugar coat it... you don't by a sports car for high fuel economy. Most people don't get the EPA numbers, nor should they expect them, unless the RX8 is driven like a grandma... but again, what's the point.

zoom44

i get 23-25 mph with the cruise set at 75 its not that optimistic. its quite doable.