New Yorker

If I'm cruising down a straight, level highway at 40-45mph and don't need to speed up, 6th gear is perfectly fine, saves gas, and doesn't bog the engine at all. Under those conditions there's simply nothing to be gained by cruising in a lower gear—except for the cool sound of the higher-revving engine and the ability to speed up without shifting. But as CodingParadox says, if I need to speed up or pass someone, I just drop it down two or three gears—which is fun, too.

scsi

i find that i can cruise comfortably at around 40 in 6th in my 04. if i have to accelerate with any kind of force at all then i down shift though

l008com

40 MPH in 3rd gear is 4000RPM. Not exactly redlining in an RX8, but damn at $2.80 a gallon, 4000rpm isn't for me unless i'm accelerating... or doing 110.

Rhythmic

From all the mpg data I've gathered since owning my 8, I've found VERY little difference in mpg based on driving habits. Maybe my car is weird, but I can cruise along at 4k-5k rpms and not see any difference. Besides it really seems that my car is more comfortable cruising 3k and up. I find that if I am at lower rpm I get more drivetrain lash or whatever you call it when the car/engine kind of stumble or jerk when you get back on the gas. I guess this could be a motor mount too?

GT34

Our trannys don't have an overdrive gear. If they did, the rpms wouldn't be up at 3500 going down the hiway at 70 in 6th. They would be down at 2k give or take. But it just comes back to the fact that the rotary runs fine at the high rpms. We've gotta true 6speed, with no od.

Socr8tes

6th gear is 0.843:1

dmc27

While low PRM = better mpg, 6th gear at 40 seems like overkill. I doubt there would be any significant gain by using 6th @1.5k vs. 5th @2k, or even 4th @2.5k.

"Front wheel drive is for people who were ******** in a past life. Karma is a bitch."

and 6th is od. It may not be the most effecient od, but there's nothing about the 8 that can be defined as effecient. 'cept maybe the use of interior space - Mazda did a great job cramming 4 fairly comfy seats in there.

GT34

If you wanna get technical our trannys have 2 overdrive gears then (5th is 1:1) and the at's have 3. But with the 4.4 rearend and having a 0.843:1 ratio makes the cars 6th gear feel more like a normal 4th. If we all were to swap out our rearends for something smaller, then we'd feel those everdrive gears.

I think what I'm trying to get at here is that with the high gearing in the rearend, our cars don't feel like they have overdrive gears. And mazda didn't do anything to incorperate overdrive into our cars. Otherwise we'd have a low rpm at 70mph.

l008com

Low RPM @ 70 MPH WOULD be nice, whens the last time you drove on the highway and went slower than that, when there was no traffic?

GT34

lol sorry for hijacking the thread

AdRoCK3217

Actually..the less you are on the gas pedal (less throttle opening) you will be using less gas. However, this isn't true if the secondary injectors are open..

Does anyone know: do our computers turn on the secondary injectors under load, or by RPM?

alfy28

um why are you in 6th gear at the speeds of 40mph? nvm the question has been asked numerous of times.

CodingParadox

alfy: RTFT

adrock: ... the secondary injectors turn on when the primary injectors max out. And the gas pedal doesn't necessarily mean much, especially at lower rpms. A barely open throttle plate will still be WOT. So you can push the throttle 10% and be at max power. Opening it the other 90% of the way won't change anything at that point, either in gasoline usage or in power made.

Brettus

iTrader: (2)

I've done a lot of testing to check this & am pretty sure they come on whenever you go into open loop .
This depends on the load the motor is under but on a flat road with no headwind it is approx 3700 rpm in 6th . any further depression of the pedal at that rpm will instantly take you into open loop = 2nd ary injectors = higher fuel consumption.
I've seen it stay in closed loop all the way to 4100 rpm but that was on a downhill run.
Of course it does go into open loop at lower rpm also if you nail the throttle but i'm unsure of when the secondaries fire up in this scenario.

diabolical1

so overall, are you happier with your '07 than you were with your '04? i ask because i'm thinking of trading my '04 in for an '07 this summer - mainly because i want the new dark blue one (i forgot the name) - but also because i think i can keep my payments roughly the same for a younger model. just want to hear from someone that has done it.

l008com

Well when asked like that, I have to say that its pretty much the same. I mean there are a few small changes, but as far as anything significant goes, the car is really teh same as my other one and so I'd say i'm just as happy with this one as I was with my last one.

myriadshalaks

iTrader: (1)

i used 6th on the highway the other day. i was going 95 when i put it there.
Of course, I could have been doing that in 4th too.

MazdaMonkey

Good luck with that. The new RL has had even more reliability problems than the RX-8!