MazdaSpeed gas mileage
 

Hey MazdaSpeed owners, what are you getting in the way of gas mileage? I've been getting 20-22 mpg / 260 miles per tank in mixed city-highway driving, with about 1000 miles on the odometer. I don't drive it like I stole it, and don't know why it sucks down gas like it's an SUV.

Have any of you had the ECU flashed? How has that affected gas mileage?

And finally, what octane gas are you using? I've been using 93 but am thinking about switching to 89...

Thanks!

I usualy get somewhere around 300 to 325 on a full tank of gas,as far as the 89 goes be carefull they suggest 93 or higher for a reason, so that it has less chance of detonation on a load and that could be a receipe for problems later also, I was wondering if that the ecu knew it was on 89 that it would sense that, and pull some timing to lessen the chance of detonaition, I dont know if thats possible,in order to do that it would have to recieve info from a knock sensor to pull timing. but when I put 93 in my 2.2 S-10 it would burn more gas weird i guess

I have a yellow 2003.5 "Speed"#1385 with 800 miles and get around 325 miles to a tank. I haven't flashed mine yet. I've noticed if the car is properly warmed up, like for at least 30 minutes, when the pedal is to the floor, I get no hesitation, no delay and great response. I only use 93 octane. I'm an aircraft mechanic, and I've worked on turbocharged-intercooled airplane engines for 15 years, and the reason for high-octane is the ablilty of the higher octane to resist detonation, or the uncontrolled burning of the fuel in the combustion chamber before spark ignition takes place. The car is designed for high octane to take advantage of the cylinder getting packed full of air, and delaying the ignition until the highest compression is reached, and lighting the fuel. The speed was built as reliable as possible, I've realized with some computer controlled safeguards, such as retarding the timing, if the engine is cold, as you guys might have felt, but this is a good thing. You have to have a stable cylinder environment for supercharging, and to prevent detonation, which destroys engines. Talk to you later, and take some curves guys, the "Speed" is awesome in turns, I found out.

the worst
 

last fill up (2 days ago) i found an amazingly low ***16 mpg***
no idea why. i work 2 miles away and have been driving my baby niece around ::drives like a granny::
no one has any ideas.

christy

Gas mileage is usually worse in the winter due to additives to prevent fuel lines from freezing. Take this into consideration when comparing fuel economy numbers.

absolutely. but 16 MPG ??? <~~ not due to cold weather. there is a problem here.

That does seem kinda low. Heck, the speeds that we have on the lot don't get driven that much, and when they do it's very hard. But, I don't think they are getting even that low MPG numbers.

Your 16 MPG sounds terrible, but this subject has come up before. It could be a fuel related thing. We'll have to ask where the owners who have mileage problems are from, and the temperatures involved. Of course, with colder air, the mixture has to be enriched to compensate to a point to prevent detonation or a lean fuel-air ratio, but how much is being used while your car is being warmed up at idle is in question. I'll be curious to see how it does once the weather warms up. I live in South Carolina, and my car is kept in a heated garage, so I haven't seen any other problems, except for the occasional ice storm. The "speed" stays in the garage, and the wife's "protege 5" gets driven. Has your car's computer been "flashed"? People have complained about mileage after that also.

i wont flash it because i dont have the problem associated with needing the flash. my car is fast, real fast from 70-80 MPH.
so i know that isnt it.
its just weird.
im just going to keep an eye on it til tues. i bring it in for a new head unit and a water leak in my left rear trunk area. oh, and another blown sub. add bad gas mileage to that and they should have the car no less than 2 weeks....

hi i have a 2003.5 lazer blue mazda speed and it has been flashed, i get good gas miliage, like around 300 on full tank. i have had very little problems too, good luck

I have a new P5 and it has crappy gas mileage too. Join the club of all us disappointed P5 owners!