Why is automatic MPG higher?
 

How come the automatic has a 25mpg highway rating but the stick has only 24 highway? Is 4th gear in the automatic a higher ratio than 6th in the stick? If no, then why the lower rating?

why the lower rating... the big horsepower difference.

Oh yeah i forgot about that :-D

It doesn't matter. I have owned both cars and neither one of them gets any where close to what the sticker says.

this is now more common with performance Mazdas. The Mazda 6 auto gets one mpg more than the manual in the city. Also, I did not see a stated power difference between the auto and manual. On the Mazda 6 the auto can come 6 speed while the manual is only a 5 speed. Mazda saved the 6 speed manual for the Mazdaspeed 6. On the rx8 both auto and manual are now 6 speeds. But the auto is again closer ratio. I would guess having closer ratios saves gas although I wouldn't know this for sure.

MPG Nowhere close to advertised
 

Hey everyone,

I love reading all of the threads... should have done that prior to buying my RX. None-the-less, I purchased a 2004 RX-8 (Automatic) and averaged less than 18 mpg after my first fill up. (108.5 miles/6.27 gal = 17.3 mpg) Stayed off the gas and most of the driving was on the highway. This is nowhere close to the 18/25 they advertise.

I am guessing mine is more like 15/19. Is this common...? I am hoping to see 20+ mpg on the highway.

it is because of the intake system, the auto only have four ports intake system, while the 6 speed got the 6 ports intake system. more air going into the engin the more gas it takes, so gas milages goes down.
you could get the 24 mpg, but have to drive like a granny and max speed at 60mph all freeway, but why buy a sport car if you want to drive like that.

They don't have any control over the numbers, it's an EPA rating.

No one claims everyone will get the numbers, in fact most are aware the rating system is flawed (Look at the ratings difference on the hybrids).

http://images.consumerguide.com/cmsi...E_LABE_600.jpg

0.69 top gear ratio vs 0.84 top gear ratio.

Horsepower rating has absolutely nothing to do with it...if anything the 4port makes more power at cruising speeds than the 6 port.

I absolutely agree, and am not at all enamoured of the gear ratios that Mazda selected for North America. Are there different ratios in use in other markets (Japan, the rest of Asia, Europe, etc.)? If so, what market has the tallest 6th speed?