gingersrus

Mine had 222 miles when I took delivery and the dealer's fill up got me only 15.2 MPG racing around Ft. Lauderdale the first couple of days. Then I filled it and drove it home to Tallahassee, and 2 tank fulls each got exactly 22.3 MPG steady highway driving 430 miles on the turnpike and interstate. So far I'm getting about what I expected.

Will see what more "normal" driving in the city gets me. I just turned it 1000 miles today.

UPDATE 1/4/04 - Third tank of gas with mixed city and country driving, and pushing it hard now and then got me 16.5 MPG.

balletsushigirl

thank you skagen, for the threadsite.
i will write a letter for sure.

and, 8_wannabe, i filed a complaint on the mazda website today actually and complained (only verbally though) in november to the dealership.

we'll see what happens!

-BSG

(and, just for the record, i do think it better to hold my breath than bend over and grab my ankles! )

balletsushigirl

are you guys forgetting that SOME of the 8's DO get the posted mileage??? there is almost certainly something defective with only some of the cars produced. i think it's a fixable problem. we just need to get them interested in working a solution.

if the car doesn't get the stated MPG, we should have the right to file suit under the lemon law and get a new 8.

-BSG

8_wannabe

Will do. Dealer called Friday and ordered the new plugs and oil pan from Irvine, said repairs would be done Monday. I'll let you know what pans out.

skagen

Yea, I agree with you. My beliefs are leaning towards a production error of certain 8's since some do get the correct mileage. Just hoping maybe there's enough people who will try to bring this to their attention.

Rotary Nut

Bumped for the weekly update.

I got my best mpg yet, 19.26!

Foureagles

Jacksonville, FL to Savannah on I-95, ~80-85 MPH: 20.1 MPG.

Savannah to Greenville, SC on little back roads, ~ 60-65 MPH, with a few rev limiter tickles & one run to 125: 21.67 MPG.

Typical town driving: 15-16 MPG.

For reference, both of our Miatas get ~35 MPG on a trip as above, 28-31 in town or wailing the bejeezus out of 'em in the mountains.

I'm not horrified by the 8's fuel inefficiency, but a vehicle of it's size & power really should do quite a bit better. Engine management in that regard seems little improved over an RX-4 with a big Weber carb.

{{{{

ptiemann

I drove 1450 miles over the holidays and after the first couple of fillups I stopped looking/ calculating.

Speeds > 120mph do no good.

On trips in the 8, we get now more "exercise" because of the more frequent gas stops. Had to stop almost every 2 hours.

MPG > HP

Would consistently log 21-22MPG on all 3 of my RX-7s driving the same as I do the 8, so I was really disappointed. However, I have to chalk most of that up to the EPA cat life quick fix and the other part to the really high rear end ratio. However, 20% improvements of 25.2-26.4MPG ain't nowhere on the horizon, no way, no how.

sritter

I have been reading the forum here because I too have been having problems with my gas mileage and oil consumption on my new RX8. I live in a suburb of Philadelphia and travel 3 miles to work everyday and have been getting 11-13 mpg. I also have had to add 1 quart of oil to the car after 1200 miles. I do not drive it hard either.

I took my car to the dealer to get an oil change and complain about the gas mileage. I thought everyone who has had this problem would be interested in what my dealer told me. The dealer checked my EEC readings and they were all okay. He also said that I was not the only one to complain about the gas mileage.
My dealer said I have 4 things going against me:
1. I live in the suburbs and the EPA forces gas stations to sell a different mixture of gas for the winter. I have seen this over the holidays when I took my car to the Pocono’s and it ran on gas from up there, which has a different mixture and I got 20 mpg.
2. I only travel short distances most of the week so the car never really warms up until I am at work already.
3. Using more gas causes the engine to use more oil.
4. The car is not broken in yet (only has 1500 miles).

I guess the good news is that after I get more miles on the car it should get better gas mileage. After April they switch the gas mixture back to normal in the suburbs and I should get better gas mileage. Once I get better gas mileage I will use less oil. So there is hope. I am going to rough it out until April and see if there is a change before taking it back to the mechanic again. But like people have pointed out before, even if it gets terrible gas mileage it doesn’t matter because I would keep the car anyway. I just want to make sure there is nothing wrong with my car. So bottom line is, blame the EPA if you live in a suburb!! (Which is what some people have posted on here already)

I believe what my dealer’s mechanic was telling me. I have it on my bill explaining these things; if anyone is interested I can probably scan it in.

BTW Oil changes cost me $7.42 at my dealership. I got a lifetime coupon for free oil changes on the vehicle as long as I own it. I just have to pay for the filter. So far I have had a good experience all around with my dealer. I would recommend John Kennedy if you live near Philly.

Hope this helps explain things for those who have had poor gas mileage.

MPG > HP

sritter, Don't count on getting better than 13.5MPG on your short trips. Rotarys are placed in cars with "long legs" and you need to stretch them out. The reason the manual wants you run the engine for at least 15 minutes is it takes that long for all the internal part to warm up enough to expand to their design dimensions. (I always make it a practice to keep revs between 3k-3.5k for 15 min, even while stopped, to let the motor get to operating temp.) You're loosing all the oil due to undersized cold part whirring around inside. On reciprocating engines you see it more clearly in pistons that are oblong around the wrist pins where the more "meat" expanding there will round out the piston to better fit the round cylinders. You'll notice more compression loss in piston motors than rotarys, when cold, but the oil consumption will be similarly high (although rotarys always consume more oil as part of their design parameters).

Btw, I'm saving my nickels and dollars for an '05 Lexus RX400h. The Toyota hybrids are the opposite of conventional drives, as they get better MPG on short trips, as they are using the electric motors for drive, exclusively (unlike the half-hearted Honda hybrids), at low speeds. You might want to look at the Prius (although only available with bare pedestrian features) which will give you 60 MPG in those short commutes. I didn't get one because my commutes are 50 miles, one-way. I felt that after making all the suspension mods to make it driveable at 85+MPH, it would loose to much of its high (mileage) performance abilities.

Rotary Nut

Well I got my worst tank to date a WHOPPING 15.23 mpg!

Mat

I have to disagree there. I've carpooled in a prius last summer and it will run on it's gas engine exclusively for the first few minutes and thus doesn't get great milage on short trips. Sure it's better milleage then most cars because the engine is so tiny, but the fact it is hybrid doesn't count much on short trips. You might as well get an echo if you're looking for short trip economy.

Mat

Someone probably pointed that out already... but here's a snip from Mazda's UK website at:

http://www.mazdarx8.co.uk/upclose/specs/specs2.asp


===========================================
Fuel consumption (EC regulation mode (???) ) (6-speed version)

combined 10.6L/100km 25.2mpg
extra urban 8.7L/100km 32.5mpg
urban 15.6L/100km 18.1mpg

Fuel consumption figures updated as of 18 September 2003.

All specifications shown may vary and may not be available in UK. To Improve Fuel Economy all European Mazda RX-8 models will be fitted with a small Boot Lip Spoiler. This is not an option.
===========================================


Nice. Why wasn't I born in uk? What is a Boot Lip Spoiler? Can we get that on the US version?

starbucks

I'm familiar with this commute, unlike some others quoted here not on the west coast. I feel I have to comment here: The under 20 mpg figures reported here on the open highway is one major reason I have held off on buying an 8, but 22-23 mpg is promising and would be perfectly acceptable to me. Btw, the reported 13-14 mpg figures around town are ok given spirited driving, but it just seems so wrong for any car to get under 20 mpg on a long freeway commute.

However I can't see how you can stand going 65 to 70 mph on an open highway such as I-5 or Highway 99 in Califronia. I would go crazy. The flow of traffic is 75, at least on I-5. Also, what were your rpms at 70?

241Commuter

Just in case anybody has trouble with Imp. gallons, this translates to the following in American:

highway 27.0 mpg
combined 21.0 mpg
city 15.1 mpg

241Commuter

Much earlier in this thread I was sparring with bobclevenger. He took much the same trip to Vegas starting in Ontario (him) and Orange County (me). he got 24 mpg going the speed limit (60-70). I got 21 mpg going 75-80. But I had more fun.

I know I'm well disciplined in getting acurate mileage numbers and Bob sounded the same. You can take this as a pretty good benchmark.

3500 rpm = 70 mph at 6.

MEGAREDS

I'm averaging almost 18 mpg. First and second tank make no sense whatsoever:

shift_zoom8

I can't remember exactly the rpm at 70 mph but I think it's well over 3000 rpm. I occasionally went 75 on that trip but I consciously stayed under 80 mph.

Eventually, I'll try a distance trip at 75 mph. But right now, my experiment is to do whatever it takes to get over 24 mpg. That's why I'm deliberately staying at under 75 mph.

Nubo

That's misleading. The electric power ultimately is generated by the gas engine and you won't go too far before it kicks in to maintain battery charge. The efficiency comes in simply as a function of speed. The main work in keeping a car moving at most speeds is overcoming aerodynamic drag, which is proportional to the cube of the airspeed.

Conventional car engines must make compromises trading efficiency for driveability so we've become used to thinking of speeds like 55mph as being inherently most efficient. That's not the case from a pure "work" standpoint. The hybrid engine can be optimized for a much narrower set of operating parameters and by avoiding many of the efficiency compromises of conventional cars the lower work requirements of low speed travel are more apparent even despite the inevitable losses involved in converting mechanical energy to electrical and then back again.

MPG > HP

From the posts I've read, only a very small % report getting 18/24, not convincing proof that poor mpg is not a problem. (so many negatives, I'm not sure what I just said!) I'm now getting 14-21 avg 19.

compaddict

My first RX-8
Miles:4417 Fuel:236.7 MPG:18.66

Second RX-8
Miles:3323.3 Fuel:195.15 MPG:17.03

Elara

hey, lookee here- there's a thread about MPG!!!

Mat

This might be stretching... and might also already have been asked but anyways.

Some people seem to have ok mileage (like, averaging 19). Some others cannot go over 15.

Could there be a relation between really bad MPG and VIN? Or cold weather?

Rotary Nut

I have to admit that this tank was a crappy one due to the coolness factor of the 8.

I was flagged down (literaly) by a person living down the street from my house and we must have sat there for 45 minutes discussing the car. All the while she was idling the curb as this guy must have walked around the car a hundread times asking all sorts of questions!!

Sometimes I wish I could tun on some sort of invisibility cloak!