yiksing

Well maybe in gear without throttle, no sparks are flying so no combustion takes place thus saves fuel.

Now please explain how the engine and transmission is wearing when you are in gear.

carbonRX8

iTrader: (1)

IMHO the best gas saving mod???? Spandex shorts, big quads, and a 14 lb Trek Madone!!!!

Allez! Allez!!! ALLEZ!!!!

Bike season is upon us!!!

LiL BenNy

ddub do you have any mods? if so what? also what rpms are you shifting at?

ddub

At that point I had Unorthodox underdrive pulleys, AEM CAI, and like 20 lbs weight reduction.

Now I have a catless midpipe and a catback, same mileage so far, NO CHANGES.

Under normal conditions I cruise between 3200 and 4000 rpms. Shifting a bit before 4000. The key to good mileage is being a smart driver. I redline at least once a day, and do many 5-7k rpm shifts. I engine brake the car coming to every stop, and toss it into 2nd or 3rd coming up to a turn, don't use the brake, give some gas and am on my way again.

JB_Rotary

I know alot of people are saying light weight flywheels/pullies are the way to go but it really depends on where you are driving. If you do almost all highway like I do having a heavier flywheel/pullies is actually advantagous becasue you get to use its momentum to keep the car moving. Obviously there is a limit to that. A light weight flywheel(again on the highway) would require more energey for it to remain at a certian speed. I ususally get 19-22mpg highway, 17 city and about 8 at Auto X's. I have the base model(weighs the least) with JIC exhaust, grounding kit, M Flash and the horrible K&N Typhoon I intake. Keeping your cruising speed under 74mph keeps the RPM's under 3750 which helps considerably. Buying another car is also a really good idea. In addition to the 8, I hava a 92 MX-3 SOHC 5speed that gets me 34~36mpg and uses cheap gas. Not a bad $1200 investment.

hoosteen

man... lightweight wheels....

lightweight wheels.

ddub

Oops, that'd be some typo action. I meant to say I cruise between 2200 and 3000 rpms, shifting a bit before 30000.

Argento Otto

If I understand this right, I think you mean "speed up" as fast as possible as long as you are in the highest gear (6th, for example) and the engine can produce enough rpms to keep the motor running with as little resistance as possible (i.e. no clutch chatter).

So, you wouldn't want to drive in 6th gear doing 35. You should speed up to at least 50 or 60 (or whatever) at the most effecient rpm, right? And this should equal the most fuel efficiency, right?

IIRC, when velocity doubles the resistance is squared? (or cubed?). So you must find the happy medium between going to too slow (engine working harder than it needs to ) and too fast (the resistance increases by a factor that offsets any high speed efficiency).

Howdy1606

just face it RX-8 get shitty gas mil.

ddub

I'm perfectly happy with 18mpg city and 20+ freeway. I don't consider that shitty at all.

brillo

Given that the older NA RX7's could get 20 mpg city is they were tuned properly, and we have a more efficient engine, with the right engine management, I bet we can get 20mpg city and 30 hwy.

I'm going to really work on that when I get my N/A interceptor, I'm going to lean out the car all over and work on the cuise maps, I should be able to push 15.5:1 when cruising in 6th, which will help.

RazzyBRX-8

It was the only way in the cold weather to get it to proper temp before I got there. Now I start it, let the RPMs drop a little and go.

silverx8

Check the brakes. Dragging pads will suck gas.

BaronVonBigmeat

You didn't give up on the megasquirt project did you?

brillo

nope, I'm waiting for the MS code writing folks to finish the ignition code. I decided to get the Interceptor as I plan on going FI later, so its a nice stepping stone. The MS is a usable solution, but the inteceptor has more resolution and features that i feel make it worth the money.

I'll try to finish that project once they get the MS code straight.

nycgps

iTrader: (1)

Im not sure about all these techincal stuff. but I dont really think that leaving your gear in will damage the Transmission or Engine much.

I mean Cars with Auto Transmission does it all the time, and Lets say for example my Father's 1995 Nissan Quest , after 10 years, with almost 140K miles. Transmission and engine still running strong(minor gasket leaks and thats about it)

and lets just not forget, Rotary use more gas/oil to run than normal engine, and its using oil in a way thats different than any piston engines out there.

ahh I dont know, correct me if Im wrong.

mysql101

CZ isn't going to help him. The Canzoomer only starts to work in the open loop., which means he'd be at high rpms to make use of it.

This flys in the face of fuel savings. In closed loop the car adjusts the AFR very well, you wouldn't want to run it leaner.

mysql101

Just monitor your AFR when coasting and you'll be able to see for yourself.

0 fuel usage when engine braking.

nis270r

yah i've read a lot on this gas mileage threads for couple weeks now. It seems to me people in the warmer cliamte generally do get better gas mileage, whereas people in the northeast or upper midwest are getting no better 18 mpg. Also, driving in city substantially kills gas, I live in NY and do about 70/30, city/highway. Normally i can only get 210-225 per tank when the low fuel light comes on. I've tried the trip meter reset trick and got maybe 1-1.5 mpg better, not much, but the car feel smoother after resetting. I have a 2004 wit 24k miles. I'm gona try using royal purple tranny and diff. oil, and maybe get a Revi intake, every little bit helps, gas price keep going up like this, i don't care what people say about owner of RX8 shouldn't be bitching at poor gas mileage, but 15-17 is just ain't gona cut it, it's not like we have 260+ hp to unleash. I recently saw the sticker on a 06 RX8, stated hp is 216 !!! Mazda needs to keep working on those flash update.

r0tor

iTrader: (1)

congrats on seeing an new 6 speed automatic car

dsmdriver

iTrader: (3)

I found an awesome fuel savings mod- my wife.

She borrowed my car for a few weeks while I was out of town, and suddenly my RX8 got 18 MPG in the city instead of the 14 that I always get. She even made it beep a few times, so it's not like she drives it like a total granny.

At least I know it's me and not the car. I'm much happer yelling at my foot than my fuel injectors.

therm8

On the last 2 tanks of gas (commuting), I cut my "normal" MPH back by 5mph (since I speed everywhere I go, it's easy ). My avg mpg went from just under 18mpg to just under 20mpg. The thing is, due to the stoplight I affectionately refer to as the "equalizer," I get to work at almost the exact same time. This is about 50/50 city/hwy driving.

The next step is to remove all the excess weight in the car. I figure I can get about 30-40 pounds off the weight by cleaning all the clothes and crap out of the trunk . Probably 3 pounds of spare change too. The jack seems kind of pointless considering I have no spare tire. You'd be suprised what a little spring cleaning might do.

swerver

My car is brand new. Got 450 miles on it now. Its springtime warm here.

I'm driving like a Granny and was dismayed to see I'm getting just shy of 16 mpg on my first two tanks. Have yet to even rev it past 6000 rpm. My commute is er,, well, somewhat congested highway driving. Average about 60mph but lots of slow downs and speed ups.....

The only thing I can think of to help (more than my granny driving) is to keep my shift points below 3800 rpm. But jeez, come on. I didn't buy the car to get passed by the real grand-ma's..........

One question tho???

How many more miles do I have (approximately) when the warning lite comes on.......................

r0tor

iTrader: (1)

best mpg mod... install a resistor after the tps sensor so the throttle only opens half as far as you push on it!!

Animagix

this is my MPG saving mod...