Ericok

It's actually a 15.9 gallon tank. So, by your math, you're only getting 7.2 mpg.

Go48

First of all the car does NOT have a 14 gallon tank. Read the manual. Second, to get an accurate number for miles-per-gallon (MPG), you need to divide the miles driven by the exact number of gallons you added to the tank. I doubt if you are only getting 8 MPG. So, note the mileage on your odometer next time you fill up. Drive however many miles til your low-fuel light comes on, fill up the tank and make a note of the gallons you pumped. Subtract the previous odometer reading from the current odometer reading and divide that number by the number of gallons pumped. Then let us know your MPG.

Also, to get an accurate picture of your overall average fuel mileage, you should do your calculations over several tankfuls and average the numbers. Your driving conditions will probably vary from tankful to tankful and one tankful of "bad" mileage does not mean the car gets that mileage for every tankful.

jammiman

well, I only put in about 13.5 gals on a fill, so I am not really using the other two. But still, that is pretty bad!

ucfracerx8

Well after 3800 miles on my car and taking the same route to work for a while and changing it up slightly, I always run 93 octane BP in it and I am always consistent between 15.5 and 16.5 MPG. I don't take any highways, it is all urban, so to me that means all city. I sit at stop lights a lot and when I can I run it out to at least 6k, with a couple 7k-9k per tank, traffic dependent of course. I am not quite sure how it is so consistent as some weeks it seems I am stopped a lot in traffic and others hardly at all, but it always works out in the end. My WRX was down to 16-17 MPG when I traded it in, so it is not like I am taking a hit and my Wife's Tribute is usually somewhere between 18-20MPG. I have never, on any vehicle gotten what is listed on the sticker, I have always been 2-3 below on each, so maybe it is just me. But I sure enjoy the heck out of the car and at the end of the day that means more to me than how much gas goes in the tank.

icyur2

Jammiman..where did you fill up at? Shell/Chevron/76 should be the only station you should use (Top Tier stuff). I have had ONE experience, where I used some other station (called Space Age), filled up, drove no more than 5 miles, and had 1/4 tank used up!!! I kid you not!!! SO, question is, did you use one of these stations? The other possibility is that when you ask for a fill up, the attendant did not fill it up properly (had a couple of instances where the pump would think it was filled up, but it wasn't - gas nozzle wasn't set properly to gauge the pressure in the tank). Anyways, hope this is the problem...

icyur2

Forgot to comment..for those owners who have higher mileage on the odometer..have you tried redlining it often? I have read on the forum that as our car gets older, lots of carbon deposits, and the best way to clear that out is to ride it like you stole it!! HELL YEAH!!!

jammiman

I fill up at chevron with 91 only. This is starting to bother me more and more as I read that everybody else gets 12.5 MPG at the worst. I pump my own gas, always. The only other thing that I can think of is that I do spend a lot of time in traffic. My drive to work is all highway, but so-cal highway, which is stop and go traffic. I also do make a lot of short trips. But with all that being said, I am still WAY below the average here. I bought the car about 6 weeks ago, and I love it too much to consider changing now. I should try the flash.

Oh yeah, GO48, I know how big the tank is in my car, without reading the manual.... thanks. I also know how to measure my MPG, I just thought that typing it all out was a bit pointless... thanks again. I don't mean to sound ungrateful, but you don't need to sound like the comic book store owner from the simpsons either!

icyur2

Jammiman..what year is your car again? Are we talking about a new car or used one? If it is new, you should of gotten a letter from Mazda about the flash (assuming it falls in the build date). What about warm-up time, etc? I warm up initially no more than 2 min. then take off, keeping RPM below 3k until it is properly warm. All other start-up is less than a minute and I still get between 17-19 mpg with at least 4 start-ups/day (2 short-distance drives). So, to hear that you are getting that type of miles, would make me think you need to take it back to the Mazda dealer to have it looked it..swapping out plugs, etc.

Of course, the traffic for me is not nearly as bad as you are experiencing..so that could be a major factor on why you are getting such bad miles..nevertheless, I would have the dealers look at it and request they swap plugs and do a thorough inspection...hope that helps...

jammiman

IC,

The car is a 2004. It is the 6 speed manual. It was purchased from the dealership, and certified. The person who had it before me (I found womans sunglasses in the holder when I test drove it) took perfect care of the car. It looks and feels brand new, so I don't think it is because of neglect. I usually warm the car for about 1 minute, it this really important with a rotary? It doesn't seem to be because it never gets cold here, so I thought 1 min was enough for the oil to get up into the engine.

I guess the only thing that I am worried about is that I may be damaging my baby in some way. I plan to bring it in this weekend because I have condensation in my drivers side tail, so I will ask about it when I get there. Thanks for the input,

icyur2

Hmm..well, being an used car, although the dealer certified it, we are talking about a rotary engine..so..if the previous owner was rough on it and did not let the engine warm up properly before cranking it, that might cause the bad mileage. Another way to look at it is if the previous owner "babied" it..in which case, you will have alot of carbon buildup..and as I stated before, redlining it often will clear the carbon. Your best bet is to take it to the dealer and complain to them about the horrendous mileage. 15/16, ok..but any less would be cause for concern. Any rotary expert comment on this?

As for your condensation, that should be covered at dealer's cost. It is a known issue with the RX and I had BOTH of mine replaced because I had it. You might want to take photos of it if you can. I didn't at the time, but since Mazda dealers know about it, they did it without proof. However, by chance, it happened again before I had the appointment and I used my camera phone to take them. They didn't need it though..

As for engine warm-up..VERY important!!! Do NOT rev over 3.5k if your temp meter is not in the middle. Doing so will damage your apex seals!!! That is why to save gas, warm up a little (1-2 min.), then keep the rev low until the meter reaches the middle, then you can have your fun. I am surprised the dealer did not cover this???

jammiman

Wow, thanks, the only thing the dealer mentioned is when moving the car (from one spot to another for instance) to let it run for a minute, or better yet, take it for a drive around the block, and when stopping, let it idle for 45 seconds before turning it off. He didn't mention any huge importance on warming it up. In the instruction manual

(section 5-4 point 6 "after starting the engine, let it idle for about 10 seconds"

and section 4-7 under "money saving suggestions" it says

"avoid long warm ups. Once the engine runs smoothly, begin driving"

I thought that said it all, I will keep that in mind, and ask about it this weekend. Is there anything else besides the oil check that I need to know about?
Thanks again,

icyur2

You don't need to let it sit idle for 45 seconds when you get to your stopping point. When your temp meter is at the middle, you can just turn off the engine. HOWEVER, if you are moving your car for short distances, it is a good idea to take it around the block, park it, then rev up to 4k, let it idle back close to 2k then turn off engine: some people rev it up to 4k for 10 seconds, then turn off engine. This will force out any leftover fuel from the block (I believe that is what causes the engine flooding for the rotary).

Yes, you do not want long warm ups. That is what kills us rotary lovers!! Once your idle meter is roughly 1k (mine is at 1.2k after 2 min warm-up), you can go. Like I said earlier also, the first start-up should be a little longer. After that, you can just either let it warm for 10 seconds to 1 min..depending on your weather.

I check my oil every 1k. Mine usually eat between .25 and .5 quart per 1000 miles.

On the side note, do you know what type of oil your car is using? I switched over to Castrol 5w20 and got the better mileage. Before, the stupid dealers were putting in 5w30..not sure what brand of oil..but I gained 2 mpg with the lighter oil.

Only thing I can think of is to change your transmission and differential oil to synthetic. Alot of hard core owners are using either Royal Purple or Redline. I swapped my dino oil to Royal Purple and noticed shifting is alot easier and smoother. Since rotary in general generate alot of heat, synthetic oil for the transmission can take the abuse. I only had roughly 1500 miles on my car when I swapped out the oil, and man were they dark!

fredw1

I have gotten a consistent 17 mpg for a 50-50 mix of local and highway driving. I had the opportunity yesterday to drive 300 miles, all highway, and got 22 mpg. My average speed was probably around 75, with windows and sunroof closed the whole time, and AC on for half of it. I use 89 octane. I have had my 8 for 15 months, and have only 8000 miles (lots of trips to the airport where it may sit for days, a short commute, long work hours, and a 4WD pickup as a winter alternate all contribute).

jammiman

IC
I am using 5w20, it is warm enough here that I don't need 5w30. Thanks for the input about letting the rotor warm up, I looked into it, and you are right, it is a bigger issue than I thought. Thanks for the heads up, I'll re-post when I get back from the dealer.

Oranje

Just checking in to post my lastest gas mileage figures. Every tank of gas meticulously logged since day one.

Enjoy,
Oranje

krauz

That is incredible... thanks for sharing your meticulously documented information...

Go48

Thanks Oranje. I have a bit over 10K miles on my '04 and my numbers are amazingly close to yours. My average for the first 7,600 miles was 20.58 mpg with a low of 17.58 and a best of 22.87.

Edit: Here's my mileage for comparison.

VOODOO8

My numbers also are very close to those of Oranje & Go48. My average on the original motor (up through when it had to be replaced @ 58K) was 20.5. With the factory reman replacement motor the numbers are running around 19.75 post break-in. I'm also a New Englander, drive the car all year long, and have a mix of driving conditions and speeds.

Jpaulspeed

On 89 octane I am getting 21.2/gal. On 91/93 octane I am getting 20.7. No complaints here. BTW it's a 2005 GT 6 spd with 19k on it and I bought it used. I let my car warm up for about a minute in the morning and I ALWAYS wind it up to 4k and turn it off. 90% of my driving is to and from work which is less than a mile from my house. I am only using mid grade gas now, I feel like the car runs better (but it could be my imagination). I don't really know what any of that means but I figured I would throw it out there.

nis270r

Wait, your motor was replaced at 58k miles? What happened? can you briefly explain what caused this motor replacement?

OfficerFarva

This is kind of odd. In city, i get crap for gas now w/ the turbo. Like, maybe 200 miles off of a tank. I was on the highway yesterday. Filled up right before the trip. I was among sum other friends w/ sti's and m3's. To put it nicely, I had several redline shifts or shifts above 6k under boost. After the night is done, and we're back in town, I look down and I have gone 203.0 miles, and still have well over a qtr tank left! That's awesome. It's like the car is saying it gets better mpg while driving in higher rpms!! Go figure.

bao0518

i just got my car 2 weeks ago and mpg does suck. 13 gal and i got 190 mile or 200 max. average out to be like 14.7mpg. i do mix of hw and city. they advertise 18/24 but i havent even seen 17mpg yet. i would be happy if i even get 18mpg. how are some ppl in here getting 19 or 20mpg?

kneele00

Damn, I'd kill for the mileage that Oranje, Go48, and VOODOO8 are getting.

I'm at about 13 MPG, and I drive an average mix of highway and city.

I keep the tires inflated, oil changed, car washed, Redline oil in the tranny and dif, and I occassionally rev to 9K to keep the carbon deposits to a minimum.

Nevertheless, my mileage bites. As you can see, I was for a while in the single digits, and most I've ever gotten is about 15. I gotta figure out what the deal is... I can't afford $200/month for gas.

Winfree

Might check your cat - if its clogged it eats gas and power; also try different brand of gas - Mobil costs like smoke but it cleans up the system

Razz1

Try going for a Racing Beat intake. You get a little bit better milage.

If your running that rich you need more air.

My latest has been 22.5 HWY and 15.38 for spirted driving 2nd and 3rd gear.