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Mazda RX-8 Gas Mileage Reports



  • avelectroavelectro Posts: 9
    My 2007 AT RX-8's best mileage was its latest fillup, 303 miles took 11.2 gallons = 27 mpg. :) This was from a daily commute of 30% suburban 10% urban and 60% traffic-jammed highway. The car just turned 7000 miles and has been averaging 25 mpg on this same commute, but I recently changed the engine oil from 15W-50 to 5W-40 which feels noticeably better (peppier).
    I keep the tires at 40 psi but that doesn't explain why my mpg numbers are so much higher than the EPA numbers. I do avoid tailgating so in bumper-to-bumper highway traffic I am leaving a deacceleration cushion space ahead of my car whereas most drivers seem to be constantly riding their brakes. I am sure this practice helps alot since I am using the paddle shifters to slow down and I think the fuel computer shuts off the fuel injection during engine braking. Also, the AT drops into 6th between 40 & 45 mph and is geared so 60 mph is right at 2000 rpm.
    I also use 1oz of Marvel Mystery Oil per gallon of fuel to help keep the engine innards clean but I doubt on such a new engine this will affect efficiency enough to notice.

    So I am very happy with my RX-8's fuel economy numbers. I just wish Mazda could get those EPA numbers closer to my reality.
  • The new Federal standards match my normal MPG 15 City, 23 High Way. But if I drive to the Cape at 60mph cruise control, I get the 27MPG you get.

    My RX-8 AT is mostly driven in city in manual mode in 2nd gear. 3rd and 4th would be dropping RPM's in down to 1200 where carbon build up is noticeable. I keep the RPM 2500-3500 in 2nd which covers all the city speeds up to 45MPH.

    I saw a piece about an engine additive that kept rotor housing shiny sparkling inside.
  • avelectro wrote, "... is geared so 60 mph is right at 2000 rpm."

    I wish the 6 speed manual's top gear was also such that 60 mph was 2000 rpm! In the 6 speed manual's case, it's 3000 rpm, so now I understand why the AT gets so much better mileage. My best recorded figure, to date, is 22.6 mpg. I'm working on trying to first get to the EPA published 24 mpg highway, and then I'll see what I can do to better it. I have heard of some manual RX-8s getting 27 highway; but I'm not yet clear on how it's being done.
  • I'm being advised by a friend not to purchase the 2004 RX8. Can anyone who has owned a 2004 or older give me any advice about it? I really do like the car but don't want to make a big mistake..Gas mileage and oil don't concern me...I'm more concerned about the engine and finding someone to work on it should it need it.

    Thanx! :)
  • ClairesClaires Chicago areaPosts: 1,222
    Since this is the MPG topic, I've moved the posts about buying a 2004 RX-8 to the general Mazda RX-8 topic. Just click the link to continue.


    Need help getting around? - or send a private message by clicking on my name.

    Tell everyone about your buying experience: Write a Dealer Review

  • rxterrxter Posts: 2
    04 6sp GT

    20 mile commute - 10 freeway, 10 city.

    Was getting 16 to 17.5 (if staying in the right lane etc.)

    Post Sep 08 reflash - dropped to 14.8 to 15.5 tops.

    Agree, when you run this thing it drinks.
  • Ok, folks I know I'm entering the realm of fantasy, but please hear me out before any profanity leaves your lips.

    So I'm in an argument with a Prius guy at work over the famous Top Gear BMW M3 vs Prius MPG episode where the Beamer got 19 MPG and the Prius got 17 MPG going around racing track.

    My point to my friend at work is that my RX-8 AT, when driven at 85-95MPH in hard Boston Mass Pike commuter traffic where lots of paddle shifting and lane changing is required to stay moving, I've been achieving 20 MPG.

    My friend contends that his Prius beats my 20MPG, but he can't produce any data from anywhere other than straight cruise control drives at high speed that show 25MPG over the 85-95MPH.

    I'm pointing at the Top Gear shows results of 17MPG that the Prius got, as evidence that when you drive a Prius close to it's performance limits, that MPG drops below 20MPG.

    Anyone got any racing or hard driving commuter data to point to? My MPG experience with my 2005 RX-8 AT is definitely a solid 20MPG when doing the fast hard driving 40 mile run from my place in western Mass into Boston, which takes me down 495 and then east onto the Mass Pike. Traffic moves out during my typical segments of the run. I go through two tolls where it's a freak'n drag race off the line most times and I get off at exit 17 before reaching the heaviest Boston traffic.
  • i think you could take any economy car with an automatic and demonstrate that, when flogged, it will get similar or worse mileage to a manual sports car keeping up with it in the highest gears possible.
  • zakallzakall Posts: 1
    I live in Canada and I own a 2004 Mazda six speed. I drive to kelowna twice a week which is around 120km (62 miles). My gas mileage is horrible, I am getting 19 liters (just over 5 galons) to 100km (74.5 miles) or 350km (218.5) to a tank. I dont think the car should be this bad on gas. What do you guys think? Plus when i go up hills the car smells terrible, not like suffer but like oil and gas mix. My engine light turned on for a week but turned off. Any suggestions
  • darkpathdarkpath Posts: 4
    It sounds to me as if your catalytic convertor is failing, and I would suspect that your ignition coils may well be shot too. The mileage you are reporting sound like stop and go mileage, so if you are not doing a lot of idling whilst stuck in traffic, then I think you should definitely assume something is wrong. The fact that your CEL came on says something bad has happened and you need to know what error code was logged before you attempt any further diagnostics.
This discussion has been closed.