First, I am not sure if auto transmissions could get the same result. I have a manual.

It requires knowing the minimum limits of each gear. From what I can tell, the gears seem to run alright but w/o much power as low as 2000 RPM (except for 1st and 2nd which can go to idle)

Here is how to get it....

Acceleration from stop to 50-65: 1-2-4-6 (skipped 3rd and 5th... all shift made at about 3000 RPM). Do not go over 70 MPH (hard to do in the RX8 but then you WONT get a ticket)

Acceleration from stop to 30-50: 1-2-3-5 (skipped 4), I guess you could also do 1-2-4-5.

Deceleration - You can stay in 5 as slow as 30 MPH, 6 as slow as 45 MPH (although I prefer 50 MPH for the change from 5-6)

I will warn you though, you will feel like you are driving like grandma when you drive this way. Everyone looks at you because you are acceleration so SLOWLY. BUT, I gained a jump from 17-19 to 21-23 MPG (4 MPG). On a 50 mile commute (roundtrip) you get the following savings (using the now 3.50 price in MD)

50/18 * 5(days) * 3.5(price of gas) = 48.61 for commuting (at 18 MPH)
50/22 * 5(days) * 3.5(price of gas) = 39.77 for commuting (at 22 MPH)

Weekly savings = 8.84
Monthly savings (* 4 weeks) = 35.36

That IS significant... What does this all mean.

If your PRIMARY vehicle is the RX8, here's what you do... for your commute, drive like grandma (e.g. adjust driving to just moving the car... who cares if everyone else passes you, are you in that much of a rush to get to work)

For the weekends, drive the car the way it should be driven... a SPORTS CAR!!!

What I am finding I am doing is that 90% of my commute now I drive like grandma, but still sneak in a nice rev up (7000 RPM anyone!!!) and still can get close to the 22MPG average.

What are others doing for the rising gas prices?

I don't want to curb my fun too much with this car, but just save it for weekends and for personal driving...

BOTTOM LINE, still enjoy your car but in your daily commute, drive it EASY and get better mileage (and your walletbook will appreciate it)

BTW, 35 dollars isn't much difference to me (just give up my Dunkin Donuts coffee and massive diet coke consumption) but keep in mind that as gas prices increase by some percentage, the savings become even MORE signficant... if prices got to 5 dollars, here are the same number:


50/18 * 5(days) * 5(price of gas) = 69.44 for commuting (at 18 MPH)
50/22 * 5(days) * 5(price of gas) = 56.81 for commuting (at 22 MPH)

Weekly savings = 12.63
Monthly savings (* 4 weeks) = 50.52

Dont be surprised that 5 dollars isn't that far around the corner. I bet our European friends are secretly enjoying our price hikes.

 

ID RATHER DRIVE 3 DAYS A WEEK HARD THAN DRIVE 7 LIKE A GRANDMA :o :D

Hang the expense :p

B...free
michael

 

WELL... I don't like grandma EVERY day. Just during my commute to work. Since I don't have a choice in transport to work (e.g. no public transport, no alternate vehicle), I choose to drive EASY for my commute. My other driving situations are all fun (And these don't get that gas mileage).

However, striking a balance is what I was trying to demonstrate.

BTW, Driving only 3 days a week wold also work as a solution. And no easy driving required.

 

i got 23.5mpg on my very first tank in the car, and i think zoom has gotten 26 or 27 on long trips.

 

Those are very valid numnbers psbjames. Starting Wednesday morning, I've been driving like a Grandma in my commute to work and when I run errands and although I haven't finished the tank yet (which is a feat in itself considering I usually fill up every 4-5 days), I'm noticing an improvement in my mileage. I've been setting the cruise control at 73 mph on the highway which puts it just under 3750 rpms (when the 2nd fuel injector kicks in). I'm currently between 1-2 notches under the halfway mark and I'm around 160-170 miles so far in the tank. I'm usually around 1/4 when I hit this many miles. I've been driving about 65/35 city/highway.

 

Thanks for the info! I always suspected that the poor mileage had a lot to do with the way the car begs you to drive.

Krankor
05 Shinka 6MT

 

Well, if you really-really-really want to improve your gas mileage without changing your driving style, you can just swap your differential gears from 4.44:1 to something like 3.73:1 or 3:55:1.

With 4.44:1 differential gears we get about 5.9 sec from 0-60mph (based on magazines and Mazda information), so with 3.73:1 we would get somewhere around 6.5sec from 0-60mph. In 6th gear, the rpms would be much lower and therefore improving mpg from the rated 17-24 to somewhere around 19-26mpg.

An average sedan with 6 cyl power makes 0-60mph in 7 sec and 20-28mpg. The RX-8 should be able to match that acceleration/mpg with gears around 3:55:1 or lower. So basically, 6-cyl sedan performace and mpg with a rotary engine RX-8.

If you really don't car about acceleration and gasoline price is a major issue, I think swaping differential gears would be the way to go. I personally would rather be able to change the 6th gear inside the transmission from the current 0.84:1 to something like 0.70:1. That should do the trick, keeping the same acceleration, but with better fuel economy thanks to lower rpms in 6th gear.

My manual RX-8 is my daily drive, I drive it smooth and I skip gears trying to keep the rpm's below 2k, my average mpg oscillate between 19.5-20.5mpg with stock gears, but I do a lot of city and bumper to bumper driving here in the nasty Los Angeles freeways (405 mainly).

 

I drive like a bat out of hell everywhere I go, almost never get my car under 85 ( lately it's been 100 plus )on the highway and I easily get 22-24 mpg. ~ 320 mile per tank @ 14 gallons. The only time my mileage sucks is when I am in stop and go traffic. I've got a 54 mile one way commute, and it's 99% highway.

 

If you do drive like that (grandma), I suspect you will carbon up the engine and greatly shorten its' life. The rotary needs to rev. to stay clean inside. Happened to a friend of mine with his 2nd gen RX-7 - only lasted 2 years. He bought a new one and drove it hard. It's still running.

Nice points to know, however.

 

I've tried the grandpa styles and definitely the mileage increases. But I found shifting at 3000 very grueling. So a happy medium with decent mileage is shifting roughly at 3500-3750. Also found that the 8 tended to drink more gas if I allowed the revs to climb faster.

 

Yep, exactly what I was thinking. The RX-8 is like a Catch-22 when it comes to gas mileage vs. engine longetivity. You can have your MPG, but it could cost you the engine in the long run. Or you can keep your engine nice and clear of carbon deposits by running it hard daily, damage to the wallet be damned. I try to keep a balance between the two myself, and I end up with a whopping 14 mpg in the city. Totally sucks.

 

Something that's always been on my mind, and was brought up by somebody else, was that shifting so near the point where the secondary fuel injectors come on could potentially "confuse" something about the car. I forgot the exact wording about what it messed around with, but I always actually thought the same thing. I mean it's like you're always "teasing" the car by bringing it up just before it opens those 2nd fuel injectors, so it probably starts preparing to open them, and then you shift before it opens. Maybe not a good thing in the long run? I've brought my shifting back down to 3000 since then. Plus for whatever reason, ever since I started shifting at 3500, my MPG dropped to the 14s and never got higher than that. Before, I was able to achieve usually in the 15s when I shifted at 3000.

 

Take some time and read the post. I still rev it up (aka redline) at least once a day and lots on weekends (Where the mileage drops down back to 19)....

 

And I thought I was driving my car hard when I took her to the red at least 3 or 4 times a day. I believe you have me beat my friend. I rarely get over 80 unless on good, smooth interstate and I don't realize I'm goin that fast. But I do get b/t 20 and 24 mpg. Not sure how I do it, but I do.

 

I'd rather visit the pump 2 or 3 days earlier then worry about all this crap. This car is meant to be driven and rev high. Get a prius or a daily driver if you're THAT concerned about your car.

this past tank i shifted at 4k to 4.25k until 3rd dropped to 4th then skipped to 6th. i drove 40% local and i got 19.4mpg
i think thats pretty damn good. i also redlined it at least once a day. stop worrying so much about ur mpg and start driving the damn thing. enjoy the car and its high redline

 

No, my friend, we're also having our particular terrific price hike, it's not only in the US (we're about 6$ per gallon and going up like a rocket).

 

You know, I HATE BEING TOLD TO GET A PRIUS just because I am concerned about gas. THE POINT OF THIS POST was to show a happy medium for those who are on a budget. Do you just assume that because you own an RX-8 you shouldnt give a crap about gas. Do you really read the post or just gloss over it.

Everyone should be concerned one way or another since fossil fuels are a limited resource. Saving a few gallons (and a few dollars) on a daily commute and not driving like speed racer to work can go a long way.

Do you have to sacrifice the fun of driving the RX8, NO!!!! Take to to REDLINE on weekends and backcountry drives!!! But going to work is just that... work. And my work commute is crowded with other traffic. I can never get going a good clip even if I wanted to unless I wanted lots of speeding tickets, or a wreck from other crazy drivers.

 

Didn't know... WOW 6 and skyrocketing. Maybe your government should take some of the taxes away from fuel.

 

Yes. You can drive like grandma but if you are in stop and go traffic it will not help. 0 MPG in traffic really brings down your gas mileage average. Just drive it like a sports car when you can and avoid traffic (IF you can). I drive in Atlanta traffic and have given up trying to eek out a couple miles per gallon by changing my driving style.

 

^liek yer sig, valpac!

 

to any of you that think this sounds reasonable....SELL YOUR CAR!!

It still blows me away how obsessed people are with MPG......go buy a GEO Metro

 

If you bought an RX8, you should have known about the MPG ahead of time. The RX8 is a driver's car. What's the point if you drive it below the power band all day long. If you can't afford the gas...you can't afford the car....SELL IT!

 

yes auto's can do that also , on the wifes 8 she drives about 42 miles each way in cith/highway and with 3000 miles on the 8 she avges about 21 , and no not driving like a grandma.. lol .. we took my daughter to collage about 180 each way and she was driving about 70 and she got about 24.5 , a lot of upand down hills

 

Is that 6 pounds or 6USD?

 

Agreed. I think of the extra cost of driving this thing as a "fun tax". I'm okay with that. And I won't be made to feel guilty for it, dammit! It's not like I'm driver a hummer...