rotarygod

Always drive downhill only and only in a tailwind!

Razz1

Leave it in the garage and only drive it on weekends.

CosmosMpower

From what I've noticed the MOST practical thing is just shift at 3000 or below in each gear ALL the time. When I was breaking in my engine I never went above 3500 for the first 2000 miles and I was easily averaging 23 mpg mixed city/highway and got 350 miles out of my first highway tank which took 14 gallons to fill back up cruising at 65 mph windows up, no AC.

Now I regularly shift 4-5K rpms in the city and am getting a miserable 17 mpg.

CarAndDriver

Drive slower.

I don't know why Mazda picked such a lousy 6th gear ratio. It needs to be higher. 6th should be an economy gear.

rotarygod

Drive slower on the freeway. There's no point in going over about 70 mph. Too many people think 80+ mph is a necessity. It's too fast for anyone to be going. For surface streets, drive faster! Aim for as close to 55 mph as you can but don't get too carried away if the speed limit is much slower.

Mazdaspeed 88

Change to the RX-8 Hydogen, but nearly half of the power lost.... driving a sportcar in the first place, we all are expecting to have a higher fc. So, enjoy it ;-)

myhui

Using cruise control does improve mileage.

The electronic throttle has a very steep curve at initial tip-in, so that just 10% of travel of the peddle opens up the butterfly valve way more than 10%. So it's very hard to manually feather that throttle to maintain steady speed on the highway.

Since it's software controlled, I wonder if Mazda would consider providing a software patch to make this peddle travel vs. valve opening curve a lot more linear. Right now, it is tuned to impress potential customers on a test drive. It is not tuned for careful driving. Proof is simple: there is no difference between 20% vs. 100% of pedal travel. All the action is in the first 20%.

Stavesacre21

...or for people that want a sports car, not a lincoln towncar.

I see their reasoning. I wouldn't hold my breath on the patch if I were you.

myhui

It is tuned like a lincoln towncar right now. I want it tuned like a sportscar, where driver inputs are considered useful rather than an annoyance.

r0tor

iTrader: (1)

stay between 2800 and 3400 rpms

(table shows instantaneous mpg)

Nubo

This dude could probably get about 45 mpg in an RX-8.

http://www.motherjones.com/news/feat...permilers.html

What he calls a "Death Turn", is just a "turn" in the 8.

Stavesacre21

interesting chart, rotor. Where on earth did you find such a chart?

and also, i'd assume load represents the % of the load? What exactly would a load be when cruising or on CC?


Nubo...that guys must live an exciting life

at least he has a few extra pennies in his pocket

r0tor

iTrader: (1)

i adapted a program i wrote for tuning an ecu that sorted through a couple thousand data points i logged from my CANscan and puts them nicely in a map. "Load" is engine load which is what most modern day ecu's use (like ours) instead of throttle postion in the fuel tables - its computed from air flow and throttle position.

what i p0sted was from a thread i did a few years back... of course data wasn't good enough for our "self taught forum experts" https://www.rx8club.com/showthread.p...highlight=fuel

i use to have a brake specific fuel consumption curve i created laying around that showed the same general info, but its on my old computer somewhere

rotarygod

I'm curious, what gear do those numbers correspond to? Is the entire chart based off of the same gear. That would make a difference if it wasn't. Generally there is a speed above which you go and your mileage falls off. What mph do these rpm's correspond to? Generally on most cars the best mph to drive at is somewhere around 55 or so if you are looking for ultimate economy. It varies somewhat though.

r0tor

iTrader: (1)

its all gears... i logged driving around for about a week.

This is why I used load vs rpm which should account for more resistance the faster you go, as well as going up and down hills ect. The thread has a speed vs rpm table but that was messy due to different throttle position and road variations for a given speed and rpm... so load was definately the way to go

But, if you go with my 2800 - 3400 rpm suggestion, that is 56mph - 68mph in 6th gear which shows someone along the way knew what they were doing.

Stavesacre21

hmm...kinda odd that so many people would doubt your factual data from your last thread...i understand your frusterations.

At any rate, a seemingly useful chart. Thanx for the info

rotarygod

I'm not doubting it. I'm just pointing out that you will not get the same mileage at the same rpm and load in 4th gear as you would in 6th gear. It's impossible. Based on that fact I just wanted to know what gear these were taken in. That's relevant information.

Stavesacre21

and understandably so...i was referring to the original post he tried to present this info in, not your reply. I agree with the variables you speak of.

otherside

80 on the freeway is my average speed=21mpg..........

zoom44

think of your right foot and your right hand as a calculator- various combinations of input from either will add,subtract,multiply or divide your mpg or power/speed.

CarAndDriver

These people are obsessed.

Michael

My grounding kit is the only mod I've ever made to a car that has paid itself off.

https://www.rx8club.com/showpost.php...&postcount=161

I'm a firm believer at this point, it's no panacea but I'll swear by it - I've had it on for quite some time.

Might want to log some data after installing one of them.

Wing5

Alright I was just recently on a road trip up and down California and I've got some numbers for crunching. I know our mileage numbers vary a lot so this may be of little consequence to most but hey here it is.

First some info...
-My car is completely stock. '04
-91 octane fuel from Chevron, 76, or Shell only. (Wish we had 93 out here)
-Drove up from LA to SF on I-5 (~380 miles)
-Made the trip down Rte. 99 to see a friend in Merced on the way (~406 miles)
-Raaaarely went over 90 mph. (Rather not have to deal with CHP)

Ok, a few numbers:
Ex. tank 1: 253.2 miles / 13.271 gallons = 19.079 MPG
Ex. tank 2: 250.5 miles / 14.001 gallons = 17.890 MPG

Compare this to my usual 120-140 miles to a tank, or 8.5-10 MPG and its a noticeable difference.
My usual tanks consist of no highway miles, LA traffic, and spirited driving. Hell when I go on our Malibu canyon runs I get better gas mileage because I have to drive about 25 min on the highway to get there X.x

Nubo

I think of it more like a cash register

icyur2

Well, after testing out for 2 weeks, I found out that my mpg was no more worse, than driving spirited vs. conservative...I got 18.6 mpg while driving very spirited, with 9K revs, twice/daily vs. 18-19 for driving conservative, while shifting under 3700rpm...so...to sum up my little test, screw the conservative driving and just have fun!!! Can't explain why some 8 owners are getting horrendous mpg, but that is something that could be due to how the 8 was built (by hand)..oh..forgot to mention that my highway sucks (19 mpg), but considering that my city mpg is around this, I'll take the balance mpg..