Last post on Jun 03, 2011 at 12:23 PM
You are in the Mazda RX-8
What is this discussion about?
Mazda RX-8, Fuel Efficiency (MPG)
#82 of 96 Re: The new federal millage rating system [trispec]
Jun 12, 2008 (1:59 pm)
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.
#83 of 96 Re: The new federal millage rating system [avelectro]
Jun 13, 2008 (6:14 pm)
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.
#84 of 96 Re: The new federal millage rating system [avelectro]
Aug 20, 2008 (5:42 am)
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.
#85 of 96 Any Owners of 2004 RX8s
Jan 13, 2009 (4:38 pm)
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.
#90 of 96 Buying a 2004 RX-8
by claires HOST
Jan 22, 2009 (11:54 pm)
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.
#91 of 96 Re: The new federal millage rating system [dwynne]
Feb 13, 2009 (10:37 am)
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.