I am happy to annouce that I am achieving advertised epa mpg on my automatic RX-8 with grand touring package. My mileage started improving once I passed the 5000 mile mark, and has been averaging 20 in mixed city and highway. I now have 7500 miles. Yesterday and today, I was able to take an extended highway drive and I got 250 miles for 11 gallons of gas. And I can tell you this was not the result of babying the car. I was driving full out on on ramps and tolls, and was cruising along at 80+ most of the day.

It was a beautiful, clear day here in the northeast, I had my favorite 60's and 70's sounds on the CD player, and I was really enjoying the day in the car.

I was happy, even when I was getting crappy mileage, but dirving the car the way I want, and getting advertised mileage put a smile on my face.

 

Previous post was from RXjoe, not from CarbonMarc, as the forum indicates

 

I'm happy to hear this. I have about 2,000 miles on my 8 and have been getting about 20 mpg with 80% highway 20% city. Hopefully this will improve as the mileage increase. Hopefully, the warmer weather will also contribute to better MPG.

 

I hope mine improves as yours does. I have 4750 on the clock and will prolly top 5K this week.

 

This is awesome news! :d

 

RN i have about the same mileage as you and the "L" reflash and the engine just seems more spirited and angry as it approaches 5000 miles.

 

i just took a road trip and put 800 miles on my 8. I got about 200 miles on each tank...about 3, sometimes i filled up early. then on one tank i got 250 miles on it i was like whoah nice! but anyway...i hope i can get random improvements like that every one in a while. Maybe it was that Morro Bay gas that was just superb hehe.

 

Actually, warm weather could have the opposite effect. You won't have to warm up the engine like you do in cold weather, so that will better your gas mileage, but I know your engine runs more powerfully with an intake of colder air. Don't know if that translates to greater efficiency, though.

 

My personal take on all this "mileage" discussions: I wish people would stop complaining about the gas mileage on the 8. Its a sports car dammit! It is meant to go FAST, and it is meant to be DRIVEN HARD. If you want economy, buy a Honda Hybrid or something like that... sorry, this is not directed towards you CarbonMarc.

The way I drive, I'll NEVER achieve the advertised MPG. I accelerate hard and I gas to the pedal, and I care less if I get less than 10 MPG. I wish people would just realize the facts. I'm sure people who own 350Z's, or G35's, or other fast sports cars, or sedans have the same stories.

 

I finally took a road trip last weekend (short, but fifty miles of highway driving each way) and saw the MPG for this last tank jump pretty dramatically. (It wasn't bad before - 17 or so - but with this tank I pushed 20 for the first time.) I'm looking forward to taking it out for a lengthy trip this summer - it ought to be fun for all the usual reasons, but I'm curious to see what happens with the MPG.

 

My 8 has more than 5000 miles and my last tank calculated to 13mpg. I let my car warm up before I move from my spot (2-3min) and then I drive the snot outta her. My shift point is 5-6000rpm unless in traffic then 4Krpm. So I doubt I'll see any improvment soon. I am asking for the L ecu flash when I get my recall work done and am thinking about CZ 1st stage.

 

I just got my oil changed again...15301. I drive the doors off it and average 21 mpg. Yes, I enjoy my car. I've been told I drive like Mario Andretti, but I love going through the gears! I'm kinda baffled though why so many of you aren't getting better mileage. I never considered the mileage when I bought my Rex, but it's nice compared to my big truck.

 

I am baffled how anyone can get 20MPG driving extremely agressively.
UNLESS, you have a large amount of highway cruising included.

My car gets 16MPG driven pretty hard. But I get 0% highway miles on there, everything is country roads. Lots of starts and stops and shifting. I never get to even set the cruise control.
The one time I went on a longer trip, with some 6th gear cruising, I got 20 MPG.

 

Newport8 wrote:

All internal combustion engines whether piston or rotary, fuel injected or carbureted, forced induction or normally aspirated need to have an air to fuel mass ratio very close to 14.7 to 1.

All things being equal, density altitude increases as the temperature rises. In other words, if you’re at sea level on a hot day, the mass of air occupying a given unit of space will be the same as that at a higher altitude on a standard day which I believe is 58F.

Less air means that less fuel can be burned so you’ll get better mileage when it’s hot. Of course, you’ll have less power so the same results could be achieved by simply not getting into the throttle as hard.

Technically, we could consider the second order effects of what’s known as pumping efficiency & thermal dynamics & probably some other stuff like wind resistance but the big thing is that the heat is preventing you from burning as much gas.

 

I'm getting pissed hearing people say "stop bitching about the gas mileage, it's a sports car . . . blah, blah, blah!" If you're happy with 10, 12, 13 mpg, then big f@$king woo hoo. Go fill you tank (which pretty soon is going to cost close to $50) every 160-180 miles and be happy zoom zooming around.

I didn't buy this car to get good gas mileage, but I'm not made of money and I did have some expectation of what kind of mileage I should get. I don't want to get into the EPA rating issue either - I know it's not by Mazda, OK. As much as I love the car, had the 8 been rated at 13mpg city/18 hwy, I doubt I would have bought it. I don't blame others for being unhappy about it.

As it stands, my milieage is not quite as bad as 13/18, but no where near what I want it to be or what it should be. I've noticed a very slight improvement as I put miles on the car, but not the dramatic increase that other people are reporting. I'm hoping to get the L flash to improve the situation, then maybe I'll quit bitching.

BTW, why do you think Mazda is coming up with these nifty new flashes to improve mileage/power? BECAUSE PEOPLE ARE BITCHING!

 

I hope I can say the same when more miles are on the car (2500 miles). I average about 14 to 15 MPG city with normal driving. I also live in a warm climate so there's no telling what I would average in a cold climate! I enjoy the car, but better MPG would sure be nice.

 

You complaint is very valid. This is the way I see it though:

I don't think it was ever Mazda's intent to make us visit the gas station twice a week. I think they had to make quick changes to to the programming of the car to meet the EPA requirements and now that they are able to gather real operating data over an extended period of time their engine and software engineers can go back and change the programming.

Maybe if Ford/Mazda was owned by BP, Chevron, etc I might believe that the MPG issue was on purpose.

Besides, what is wrong with fixing something because of complaints? Isn't that what you want them to do? The alternative is to do nothing.

You may say, "Well shouldn't they know about it?" but... I work as a system admin and no matter how much we spend on complex monitoring systems/software, sometimes it takes some complaints from customers to actually find a problem. The way it works for me may not be the way it works for you so I may never see the problem. Based on the "MPG is good for me and getting better" vs "The MPG sucks" on this board, I think that is exactly what happened/ is happening. Tracking something as random as works for one and not the other is difficult. Especially given that despite the handmade engines, our cars are for the most part exact copies of each other.

Also I believe in the notion that rotories get better with age. Combined with the fact that obviously Mazda cares or they wouldn't be pushing upgrades out like this in rapid succession you may get what you paid for and maybe more.

 

Sitting for 2-3 mins warming the engine up is a waste of gas (and time) - just drive "easy" until the engine is up to temp and then you're set, there's really no need to warm the engine up prior to starting off. (Just make sure the engine has warmed up by the time you get where you're going and want to shut it off though)

 

Could the improvement have less to do with whatever flash has been done (K, L, M) and more to do with gasoline suppliers switching over from winter mix to summer mix?

 

its a fuken 1.3 litter how can it guzzle so much gas?!!! I mean some SUV's get better mileage then the 8. I KNow its a sports car but **** if u can change the hp rating change the mileage also. I mean the 04 Cobra gets 18 mpg. Thats pretty damn good, and thats not from the EPA thats from a magazine i read it from. AND its a v8 AND it has 390hp and 390 tq. i just dont get it...

 

Over 7000 miles in 10 weeks, I've averaged 19.4 MPG overall. Since about 3000 miles, my average is 20.1.

I make sure to rev it to the redline each and every day. I have a mix of 80% highway and 20% city (104 miles each day total). In the city, I'm often sitting in 3rd or 4th for the throttle response. I sometimes do hit the gas hard to get around some bubba on the road.

That being said, I didn't buy my 8 for the MPG!

 

I agree with Krustyclown. I think most people who are upset
about the gas mileage may have had the wrong idea. Yes, it
wouldv'e been nice if the mpg was about 28/30 for a 4 door
sports car, it would definitely push more cars, since they are
selling the idea for couples with kids that dad gets his "zoom-zoom" out while he gets the kids from soccer practice! But it
is a sports car, while it is the most brilliant concept I have ever
seen in a vehicle which is why this car will be very successful, I
never forget it is a sports car, not a econobox. But the mpg is
increasing with use, so thats whats keeping me going. I won't
go into the horsepower/mpg debate, but I do remember Mazda
having to apologize about the hp for the 99 Miata.. Maybe thats
whats sticking for some mazda fans.

 

Demon RX-8, Im getting 12- 13 mpg and agree with you 100% I am not made of money either and based on the EPA ratings expected my RX8 to match that of my former 2000 Honda Accord VTec 6.

 

I have been 8008 miles and gotten 19-20mpg driving normally and not racing anyone, MT. On a trip back from Beaumont, TX today I got 24.5 mpg, driving 73 mph on cruise and at around 3700rpm. Best so far by 2mpg and I haven't had a reflash. I'm pleased with that!

 

Well said, DemonRX-8, I couldn't word it better.

I got 19 to 20 mpg before I had the L reflash done this week, that's 95% highway driving, now with obeying speed limits (just got my 3rd ticket within a year).

-Peter