I've owned three cars while living and working at the same locations for 20 years, and I've maintained periodic mileage records. Excluding fillups when I took long trips, this gives me a good baseline for comparing gas mileage in virtually identical driving conditions, using the same gas stations.

Mazda RX-7 18 mpg
Dodge Stealth 20 mpg
Mazda RX-8 15 mpg

RX-8's low mileage is costing me about $30 a month extra, an irritating but financially trivial amount, IMHO.

What really bothers me is the increase in fillup frequency, which steals time from me. I hope Mazda has a good explanation and a fix coming.

 

I think part of it has to do with the rather small gas tank...larger tank would result in fewer fill-ups. By comparison, the G35 sedan has a 20 gallon tank with a quoted trip range of over 400 miles. The 8 with its tank just under 14 gallons has a quoted trip range of about 285 miles...but I'm assuming that number is if you run the tank bone dry. Most of use seem to be filling up at about 200-225 miles...which means we're filling up quite often.

 

According to my owner's manual the 8 has a fuel tank capacity of 15.9 US Gal.
It looks like 300 highway miles per tank is feasable, and after 5 hours driving I am ready to stretch my legs! 400 miles per tank would be nice as it would allow L.A. to S.F. non-stop, but that's not gonna happen in this car.

 

This is one thing that would give me pause in buying the car. I had a (german) Mercury Capri years ago, stuffed with a big V-6. Unfortunately, the geniuses at Ford never increased fuel capacity over the standard four banger, and it seemed like I was spending half my life in the gas station. My MP3 gets over 320 per tank, which is something I appreciate, as I drive quite a bit. It sounds like I'll be waiting for version 2.0 on this one.

 

If we really do have 15.9 gallons, we should be going a lot further before we're filling up. Say (17 x 15 gallons), so 250 miles should be a piece of cake before most of us have to visit a gas station...now where the heck did I get that 14 gallon number from...must have made it up LOL.

I used to fill up right at about 300 miles with my old car. When I did more freeway driving I could get 400 miles out of my old car but that was running the car on fumes.

Now that I live in the city and don't do as much freeway driving I'm actually happy with 17-19 mpg with the 8.

 

You guys need to stop blaming Mazda and start yelling at the EPA, since they're the ones that screwed up the MPG ratings. Mazda has NOTHING to do with it, aside from building the car. They are not allowed to state their estimates.

 

Well, I think the "Low Fuel" warning light comes on at somewhere around 2 gal. remaining which is 13.9 gal. used, so that may be where you got that figure.
I am just trying to figure out what the usable fuel capacity of the 8 really is. I have run it to below the E mark and it still took fewer than 15 gal. to fill it.
Why oh why can't automobile manufacturers give us ACCURATE fuel gauges?

 

I think everyone needs a nice 4 hour road trip on an uncrowded highway like I had last weekend. I never got much better than 16MPG prior to that, and hitting 22MPG was pretty sweet, got rid of my only complaint with my 8.

22 isnt great, and it isnt 24, but its a whole lot closer than I ever thought my car would get to the EPA estimates.

 

I am fairly certain that the usable amount of fuel in the tank is approximately 15.3-15.4 gallons. I know this because I ran out of gas back in September. I walked the remaining .2 miles to the gas station and got exactly 2 gallons in a small gas carrier and put that in the car. When I got to the gas station with the car, I put 13.3 gallons in it, and I was filling it up as much as I could. I maybe could've squeezed another .1 in the tank, but that would've been it.

 

They test all cars the same way and they don't seem to have the same "screwup" with other cars. The RX-8s tested by the EPA obviously were "better than average". What a coincidence...

Mazda, on the other hand, does have a history of screwups and they did change the ECU software at the last minute...

The EPA was not the one that touted how the RX-8 was supposed to be so much more fuel efficient than all previous rotary offerings.

 

I repeat, Mazda is not to blame for the stated MPG, the EPA has a screwy test. Automotive News even had a recent article about how the test was not up to real world standards, and ALL vehicles get less than the stated MPG, on average. Granted, some people here are getting really crappy mileage, but it's not due to anything Mazda claimed.

 

In regards to the EPA I heard Toyota actually wanted to state the MPG lower for the Presario but there is a law that you must state the EPA numbers and can not report higher or lower so they had to show a higher number. The test favors hybrid cars.

 

Hey Bob, you ran the fuel gauge past the E mark and it still didn't take atleat 15 gallons to fill up? Hmm...the way I assumed it was that the halfway mark on the fuel gauge is at 8 gallons, half of 15.9 right? So then if it goes PAST the E mark then that gauge is definitely off. Bah. Looks like no one has gotten an official word from Mazda, might have to send a letter myself.

 

lets all send a letter to show mazda how many buyers are concerned about this subject. Anyone have an address??

 

Yeah, if you assume a linear scale from 0 to 16 the reading is about 1 gal. off at most points on the scale. IOW, if the gauge says you have used 12 gal. (1/4 tank left) I have found that 11 gal. fills it.

Now this is not just a Mazda problem. Almost all auto makers install fuel gauges that are inaccurate. And they may well vary from car to car also. I would just like an accurate fuel gauge, at least near the bottom of the tank.

 

The problem is that they have to build cars for the lowest common denominator of human beings these days. Like the people that buy hot coffee and then sue because it's too hot.

They need to install lying gauges so that people will be scared enough to go and get gas instead of run out.

The same reason why they installed that fake oil pressure gauge. So many people would call about the oil pressure that they were getting and how it was moving or how it was higher than yesterday, etc. that Mazda just realized that it wasn't worth the hassle.

The gas gauge in my Protege is dead accurate. When the needle touches the "E" line, the car will start sputtering and run out of gas. The low fuel light comes on about a gallon before then. But it is so because I had to remove the pump/sender, etc. and when I installed everything back, I aligned it differently than the way it was from the factory.

 

If you would like to complain officially to Mazda about your low mpg please write to:

Mazda North American Operations
7755 Irvine Center Dr.
Irvine, CA. 92618-2922
P.O. Box 19734

ATTN: Customer Assistance

Include:

1. Your name, address, and tel. number.
2. Year and Model of Vehicle
3. VIN
4. Purchase date and current mileage
5. Dealer's name and location
6. And your questions/comments about mpg or any other issues you would like to address.

You can also call 1-800-222-5500

Remember if you call, take a log of the person's name, time of call, subject matter discussed. This way you have written proof and information that can be recollected later.

 

I just started a whole new thread in the general discussion, it has an address. Please check out this thread:

https://www.rx8club.com/showthread.p...threadid=17649

 

If an admin sees this, and feel it appropriate please sticky this thread. Thanks!

 

I just got my 8 back from the dealer where they had to replace my throw out bearing with only 1300 miles on it. Anyway the mechanic that is certified on the 8 told me that he contacted Mazda about mine and one other person in my area complaing of really poor gas mileage. Mazda told him that they have had many complaints from all over the nation and that they are looking into the problen. I don't know if the mechanic is trying to placate me (since this is my third time complaining about it) or if Mazda is finally on the ball but maybe there is hope.

 

bump!

 

thanks skagen, hopefully we'll get mazda to do something about this.

 

don't hold your breathe.

 

 

rather hold my breath then just bend over and hold my ankles.