Chrisbert

Winfree, he was hit by a Ford Tudor.

NotAPreppie

In general, the most efficient speed is the lowest speed you can go in the highest gear. Given that most interstate highways have a minimum speed limit of 45-50, that would be your most efficient speed in 6th.

Joe_914

I'm with you. If I was worried about gas milage I would have bought something else. Besides the wife drives the RX-8 and puts here own gas in it.

As far as effciency? don't know how these rotor things work.
But my 914 with an aggressive cam and carbs and header I get better milage @ 80 that 70. Something to do with air speed through the induction system speeds up and fuel is atomized better through the carbs just before the main gas jets come in. Then milage goes to hell and car speed is really fighting aerodynamics. Like pushing a brick.

BTW what is the Cd numbers for the 8?

Aseras

drag is .31 according to mazda..

skhmund

i read this on another thread but it said that peak gas mileage is around yor peak torque which in the mt is at 5500rpm, is dat correct, please correct me if im wrong.

Joe_914

5500 RPM ? That would mean that the injectors are @ full duty cycle. Do you know how much gas an injector can flow wide open? ALOT
just for reference previous car MCS averaged 35 MPG but keeping my foot in it and maintaining peak torque not only resulted in really haulin butt but the computer indicated 9 MPG

which is about right as I average 6 MPG on the track with the Porsche.

Animagix

i cruised at 95mph. i went 190 miles and had a 1/4 tank of fuel left.

Jedi54

iTrader: (7)

Easiest question I've seen all day.

The Answer is: 87 mph. Everyone knows once you hit 88, the flux capacitor comes on.

toxin440

i can make it all the way from here NE Fort Worth, to Magnolia TX, about some 270 miles away on one tank... even though I have cruise control i didnt use it on the last trip because I was having some "fun" in the car. (saw my speedometer hit 140 for just a bit) wheeee!

But I just drive it and have fun, milage is always in the back of my mind, in the city its always going to suck, 200 for a tank is an avg of mine for 100% city driving.

captain mercury

i've learned to just 'let it go'

willsrx

I get an average of 190 before the e light comes on. I have given up on getting good mileage, I just have fun now this car is too much fun to shift at 3,750 rpms.

DOMINION

100mph!

MazdaManiac

iTrader: (3)

G*D D*MN! I've never seen so much misinformation in one thread!
Full injector flow at the torque peak? 55 MPH median speeds? Lowest speed in the highest gear ?!?

There is a somewhat "magic" point at which the target A/Fs change on the RX-8. It has a lot to do with the calculated load, which is based on throttle position, vehicle speed, airflow, temperature and time at or above a certain RPM.

On my car, this cross-over point is about 4200 RPM.
If you have access to a WBO2S, you can find this point yourself. Just drive at different constant RPMs above 3700 RPM and watch for the A/F to drop from 14.5:1 to 13:1 at some point.

Keep the car below this point and you will maximize your fuel.

That said, I have done several LONG trips in the past few weeks. 500 to 1000 miles at a time. On these trips, I have kept different average speeds for each tank of gas.
I did legs at average speeds of 65, 75, 82, 95 and 105 MPH.
The 75 MPH yielded the highest MPG at 22. The 82 and up yielded identical MPG numbers at 16. 75 was 20.
I also had an additional leg where the "average speed" was about 95, but that was because half of it was a 60 (lots 'o cops) and the other half was at 135+ (fun with Corvettes). I don't think that one really counts, though my mileage was about 16, which is my normal city mileage.

Animagix

Leave it up to dominion to deliver the best Sig pics. kudos, man.

Glyphon

actually, 0mph will yeild the worst possible fuel economy. why? because you are going no where, yet you are still using fuel, meaing you are getting 0mpg. i don't know about you, but i consider 0mpg pretty damn poor

Aseras

welp drove to Miami and back last night. it's a full tank round trip. did 100 mph 2/3 of the way there, got into traffic in lauderdale and did 80 the rest of the way. got 152 miles right at half a tank. did pretty much the exact opposite coming back, actaully went a bit faster in places and idled a bit @ some construction. pulled into gas station with gas light on. 305 miles on 13.546g with gas spilling out. that's 22.6 mpg.

therm8

I have the 4AT, so I've got the .69 4th gear vice the .84 6th gear.

The last 3 trips, same route, same distance, I used Shell V-power (always gives me the best long trip mileage): High and low #'s depend on which leg of the trip I'm on (half is coastal plains, the other half is 2-3000ft elevation and hilly).

80mph (3300rpm): 24-26mpg
75mph (3000-3100rpm): 25-26.x mpg
70mph (2800-2900rpm): 25-26.x mpg

So I just go 80mph .

Using any other brand of gas, you could subtract about 2mpg from those numbers.

skillmaker

The speed at which I get the best gas mileage is directly dependent on the speed of the 18-wheeler that I am drafting behind. Even with a slick car like the 8, wind resistance is a real drag on MPG.

When no 18 wheelers are to be found going at an acceptable speed, I get the best MPG at approx 63 mph.

Aseras

I find it's cheaper to be all alone than to fill in all the holes and dings from the rocks flying behind the truck/car I could tailgate...