What kind of mileage can I expect at 100 & 150 mph?

I was thinking 20 mpg @ 100, and 10 @ 150.

 

I think at 150 mph unless yer on a track you shouldn't care about mileage. If you're doing it on the road welp... hope ya hit something.

Keep in mind you need about 5 miles to hit 150mph.

At 100mph though, figure low teens... I'd say 13/14, because you'd be revving hard and ideally staying in fifth gear to keep the juice up. 6th is for gas economy.

 

Well if the Rx-8 can get up to 95 in the 1/4, and then can max out 4th gear within another 1/4, then I hope that the Rx should hit 150 in 5th within another mile. 1.5 miles total.

So if 13/14 is achieveable in 5th, what could I get in 6th.

 

You won't hit 150 in 1.5 miles. There's almost no car that can do that, unless you talk McLarens and Ferraris.

I'd say at least 3 or 4 miles. Car and Driver give themselves 5 miles of clear road before they hit top speed, and they usually mention that it comes right before the 5 mile mark.

 

There was a Motor Trend shoot out a while back.

http://www.geocities.com/MotorCity/3...20Acceleration

I would expect that the Rx-8 should cross the 1 mile mark at about 135-145 mph.

 

It's a moot point anyway.. where can you go that you'll hit that speed anyway?

 

On any 400 series hwy in and around Toronto, Ontario.

 

I am always thinking in New Jersean terms... nowhere around here to get high speed... not that it matters. I know a good place to carve some corners

And a few empty lots too... *whistle*

 

But wait, in the thread below, you said the WRX and the Neon SRT weren't any good because they had no top-end speed (even though the Neon SRT has a 1/4 mile trap speed that will likely be higher than the RX8):


http://www.rx8forum.com/showthread.p...7453#post27453


So, which is it?

 

I was talking about top end torque, and it's already proven that at the upper end of the rev range that the WRX will fall behind even an Acura TL because it can't get to the upper eschelon of the speedometer. These rally cars don't usually get over 100 so it's kinda by design.

 

So you regularly go over 100 MPH in Jersey? Dude, you gotta show me some of them roads? :D

Seriously, I agree with you that rally inspired cars (and the somewhat similar FWD Neon SRT) aren't designed for top end acceleration, but of the four in this group (Neon SRT, WRX, EVO VIII and WRX STI) only the WRX will have a lower trap speed in the 1/4 mile than the RX8 (the best indicator of top-end acceleration that is readily available as far as I know). Since, the WRX lists for about $3-4 K less, you may even consider that a mitigating factor.

 

At high speeds above 100 MPH, the key element restricting the speed of the vehicle is air friction.

It takes 8 times more power to drive at 200 mph than 100 mph, but you are moving twice as fast. Which becomes ultimately a quadratic relationship, thus the gas milage at 150 mph will be about 2 times worst than the gas milage at 100 mph.

My guess is that 100 MPH will be about 20 MPG so 150 will be about 10 MPG. Which will be a gallon about every 4 minutes.

So MikeW, it looks like we are in agreement.

-Mr. Wigggles

 

it depends on a lot of things, but mostly rpm and throttle position: the higher your rpm, and the more open your throttle is (ie: accelerating vs. cruising) the more gas you're using, and thus your mpg goes down.

to maximize your consumption, you would want to use the highest gear at the lowest cruising rpm possible for that speed (it's obvious you can't do 20mph in a parking lot in 6th).

 

who says? i really like going super slow and blocking traffic! :D

 

When you do it in an RX-8, you'll be stopping traffic as they sit there and drool!

 

what i mean is that while you're doing 20mph, you can't use 6th gear without stalling the car :p

so, i don't have all the gear ratios memorized, but if you were at 2500 rpm in 6th (which is 0.768 or some jargon like that, with the 4.444 final drive) with your foot barely on the gas, you'd be at "max fuel save" velocity.

 

Here (Germany).
For me, fuel consumption at higher speeds will be one of the main deciding factors whether I get an RX-8 or not. Not because of money (hey, fuel is only close to $5 a gallon over here), but because of operating range at higher speeds.