13 MPG!!! Help!!!
 

I just purchased a 2004 Mazda RX-8 with 26k miles, and even with keeping the RPMs down Im only getting 200 miles out of the 16 gallon fuel tank. The Mazda dealership is at a lost (And doesn't seem to care in the least), and I'm not sure what to do. Has anyone had this problem or have any suggestions?

No, you are the only person on this board getting bad gas mileage.

Okay, That previous post was just cruel.

There are many folks that have had gas mileage issues. Search the board for some appropriate answers and ideas.

Also, to achieve best fuel mileage, shift at the manufacturers recommendations for shift points (read the manual). Loosely translates to shifting at 3000rpm. Also great if you like shifting, as you'll shift 4 times to get to 40mph.

That's just mean dood! =)

wow...thats deep...there are several of us that get this kind of mileage....at best i have gotten 240ish out of a tank with mixed driving.....if you search out this forum there are plenty of threads that deal with this....you are not alone and mazda will do nothing about it....it is after all a sports car so just enjoy it and drive it like you stole it.....do you know if your flashes are current and if the car has had its maintenance done?....that could help some....there are some abnormal cars out there that have also brok 300 to the tank but they are pretty rare....

where are you located. at or mt? what fuel do you use

it is NOT abnormal to get more than 300 per tank- thats just highway driving

16-17 here..

~20 mph here.

So do you drive EVERYWHERE at that speed??? :mdrmed:


I'm getting 20-21mpg out of my 06'. I even squeezed 314 miles out of a tank once. I feel for your 12 though....that sucks. Almost sounds as bad as driving my Jeep that has a 360 V-8........ it ranges anywhere from 7 to 8 mpg.

Love the car! Would just prefer the 18-24 MPG that they advertise. Thanks for the help though.

I float between 220 and 240(250 once) per tank(14-15+ gallons)...

it would be nice to have a 300 mile range

It's a MT in eastern PA north of Philly. I've been trying to shift around 3k RPMs.

How much gas did you fill up when you got 200 miles on your tank?

If you do the math, at 200 miles, you are putting in approximately 16.67 gallons in your tank. By my estimation, that is practically bone dry.

More realistically, if you put about 14 gallons in your fillup, at 200 miles you are getting 14.3 mpg. Still sucks, but sounds a little more realistic.

I am almost always north of 17mpg, closer to 18mpg most times. Only a couple of times have I dropped below 17. I'm guessing that is closer to the "norm". On a "full" tank, that is about a 220-230 mile range, and a 13-14 gallon fillup.

I filled it up with 15 gallons last time. I purposely let it get really low to see my MPG more accurately. Every 50 miles it goes down a quarter of a tank. Maybe I'm getting 13, but no more than that. It has been serviced recently, and doesn't need a tune-up yet. I put 93 Octane in it, and the air filter and housing is clean. The tire pressure is good, and I haven't been using my A/C either.

get it out on the highway and FLOOR it. Keep it in 3rd if you have too and run it over 7K for a while.

change gas stations. use quality gas.. the cheap shit is just that. 87 gets me better milage. good 87 is better than cheap 93.

I'm a good 50/50 of city highway and I always get about 22 mpg, more on the highway, but you really have to run the car and keep it happy.

if you still have crummy gas mileage one more thing to try.. after driving. park, go into nuetral and rev then engine, hold it steady at 5k or so until the car gets hot, you want the temp gauge to start moving, or to hit the too hot fuel cut. make sure your thermostat is working. if it's sticking it can kill your milage.

Welcome to the club!

First thing you need to do is use 3rd grade math to properly determine your MPG.

Reset your trip every fill up, then take the miles you've made and divide it by the number of gallons you put into your car when you filled up.

By doing this A) you get the proper MPG (which will be higher then 12), B) you dont have to drain the tank completely to find out your MPG, C) You stop making threads about 12mpg when you're really getting better then that.

Example, 250 miles on my trip, i put in 13.5 gallons when i filled up...

250 divided by 13.5 = 18.52mpg

First of all, I said I put 15 gallons in it. I only got 200 miles from it. I am on extreme E and have used between 15 and the max of 15.9 gallons of fuel. Hence around 13 MPG which I previously stated the correction from 12. Thanks for your input though.

use my simple 3rd grade forumla on your next fillup, let us know what it says.

And all that is with me purposely driving like a granny. Can't imagine if I almost redlined it alot, lol! Probably get like 10 or 11. Oh well, I still love her.

I know very few third graders who are driving enough to calculate their gas mileage.

this car NEEDS to be redlined... frequently. driving it like a ganny WILL kill it.

So what is good gas? Mobile, sunoco, hess?????????

I remember there's a topic somewhere here that has a list of "certified" stations. Included were Shell, 76, and a bunch of others. The suppliers of those gassolines supposidly meet a certain set of standards. Anyways, just search for that topic.

wow... didn't realize these 3 pages were all from 3 hours

I just filled it up again. I'm quite aware of your little 3rd grade equation. I went 197 miles and used up 15.2 gallons using an average of 12.96 MPG. I was previously stating a guesstimation of the MPG and gee...I was quite close wasn't I, CLEOENT. To the rest of you I very much appreciate your advice and I will try high revving it. Anyone think I should use a fuel injector cleaner on it? Not sure if that's alright with a rotary.

You must be doing city driving and alot of warm up time and short trips.

It should be more like 16.7 MPG

I can get 22.5 MPG on all Hwy. All city driving and short trips kills your MPG.

Try going up a steep hill. If your car bogs and can not accelerate normaly the you have a clogged CAT. That will kill MPG. CAT is covered under warrenty.

I'm pretty new to this club and I am already sick of all the "Mileage" threads. I know I can just stop opening these links but I'm afraid I'm addicted to this board and I love hearing people whine about how life sucks.

If you can't afford gas why not buy a Honda or Toyota? I wonder if other sports car clubs and off-road truck clubs complain about mileage....

I'm not complaining about the car. It calls for 18 MPG city driving, 24 for hwy driving. I'm getting 13 so therefore there is something mechanically or electronically wrong with my car. I seek to correct that problem. That is all. I'm fine with it running the way it was designed to run.

How many short trips do you take per tank?

Stop complaining, 12 - 16 mpg is normal for some 8's.
When you get 9 mpg like some of us you'll earn that right!
Besides, my knowledgeable service dept told me that 9 mpg is normal.
My bad mileage is due to grannying it, No wait! It's due to racing my AT
with bad gas...
They wouldn't lie to me... would they..!?!

Seriously...
Mazda doesn't have a clue why some 8's get poor mileage and others get 20+

It's easier to blame the customer for something they're doing wrong...

I do live in a small city, but it's surrounded by highways so it's a pretty even share of driving conditions. And as for short trips, probably the average is 15 min. considering in a city everything is pretty close including my job. I do give it at least 5 minutes before shutting it off as recommended.

Lol! Too true Eyeball! I think I have to agree with that. 9? Damn!

not true- look at the sticker again. 18 is a median with 15 being possible driving like the test. your low may just indicate you are not driving like the test.

not saying you dont have an issue- just that your mpg doesnt automatically mean there is something wrong with the car

you let it sit at idle for 5 minutes every trip or close to it before shutting it off? does it sit that long running after start and before you start driving? theres your issue then

Lol! No, the manufacturer recommends to not run a rotary for less than 5 minutes at a time. And as I stated, I have tried driving it at lower RPMs to preserve the fuel. I have a degree in Automotive Technology, and I am a Service Adviser at a Mercedes, Audi, Porsche dealership. The mazda specialists are at a loss as well as me as to why I am getting such shitty MPG. It is below spec. I am just trying to see if maybe someone else had this problem as well and somehow corrected it. I don't believe the cat is bad because the o2 sensor is reading fine downstream. The air intake seems to be cleared and functioning properly. There is not any codes. The fuel trim is where it is suppose to be. Small things like the tire pressure are fine. I have tried to shift differently to see if that helped, but it didn't much. Air filter is fine, it is not due for a tune-up for another 10k miles and it recently had the routine service performed. I'm thinking maybe fuel injection cleaner, but I am not sure if that is safe for a rotary.

Tis normal. You're lucky to be gettin 200. i'm more like 185.

What you are experiencing, sir, is not a problem but a feature.

I read a thread in the last week or so where the guy (or girl) replaced their cat with a highflow one and got better gas mileage and better performance as a result. Before the swap they were getting some crappy mileage and the cup holder would boil water. I do not remember the particulars but I believe that they stated the O2 sensor was giving off normal readings before the swap. After the swap the cup holder was cool again and they got better mileage. Do a search to get the actual statements before you quote me on anything.

it's not normal... i've had two rx8's and both got around the same mileage. about 240 per tank in the city and about 280 on the highway.

his mileage sucks and should not be accepted because a few others are experiencing the problem.

well the degree could be your problem :D: i keed i keed

ok- do not believe that the cat is ok because the O2 sensor is reading fine and there isnt a code. i could link you to a whole slew of posts that had bad cats and no cel. it will eventually but only when the honeycomb breaks lose. and even then it might not. just recently had another one. a freind had an issue and after driving the car i and others said bad cat. of course his dealer said no CEL etc. he went to another dealer that dropped the cat and pieces fell out. pull the cat and physically look at it from both ends.

also pull your coils and look at the back. if there is evidence of melting or burning or the plate they sit on looks like there was arcing going on change the coils. pull the plugs and see if they are fouled. also check that you have the new style plugs and not the old style.

A few?

what would you consider to be normal for all city driving?

On what would you be basing your assessment?

Well, from what I experience, the longevity of each fuel tank is greatly effected by the amount of short trips. I drive to school, to/from lunch, and home form school every day. That is a ton of short trips and if I do not drive any highway in that time, and use up the whole tank, I get about 200mi or so. If I drive with highway included, the number can get up to around 240. I never realized how much the different kinds of trips could effect mileage before this car...

thats exactly it- that extra trip around the block for lunch(really 2 starts adn 2 short trips) will kill the mileage especiall if they are not accompanied by a nice easy cruise on the freeway home(no stop and go just light throttle highest gear possible etc)

Heh, I'm not the one complaining though :)

I've read somewhere that car companies test their cars' mpg basically on a treadmill so there's little air resistance and friction... in other words the most ideal conditions. So I would expect the mpg less than the advertised number.

I also got 12-13mpg all the time I shifted at 6500rpms to 7500rpms

Thanks for the advice. I think I'll look into the cat issue first. And the plugs as well.

As some have mentioned the gas you put in can make a big difference. I just got back from a trip and got 22.9 mpg on 87 octane and got over 25 mpg on shell v power 93 octane more than once with almost the exact same driving conditions. My car obviously likes that specific kind of gas.

200 miles on a tank? Same here.

However, I also have a 2nd car that gets 25mpg city and 30mpg highway that I can drive if I ever tire of spending $45 a week on gas. :)

250ish per tank ,,mostly freeway at 4000 rpm