But if you are going to drive around like that, then you might as well sell the 8 and get a Geo Metro or something. Sounds economical, but also sounds like 0 fun

Dennis

 

does a geo metro come with leather seats? . I could redline my car like some but i need this thing to last for a while so i dont drive scary fast very much at all. As for 0 fun, like I said when I feel the need to drive it hard, I throw the 93 octane in and have fun like the last couple nights. In all honestly if i wanted a car that i drove hard constantly i probably wouldnt of chosen the 8, even though i love my car more than all but about 15 people on the earth.

 

Ok....my 'first' tank in my new '8' yielded 19.7 MPG!!!! But......I'm driving it pretty easy. At any rate, it looks/sounds like my MPG will be better than most?!

 

Forgot to add, I have a MT.

 

19.092 average mpg with 23,xxx miles on the car. Highest is 23.712 during a road trip and lowest is 7.200 at a track day at Road Atlanta. The car is a 6 spd Touring Package.

Standard Deviation is 2.36 mpg so I'm pretty much in control except during a track day or extended autocross. 245/40's on the car.

 

hahaha thats pretty funny i use 87 most of the time since the gas is really high around here but i redline the car a lot i now read people say their car is pinging or doing other crazy things with lower octane i'm a idiot someone describe what they mean.

 

I bought my new 6 speed a couple days ago. I travel 86 miles a day, round trip to work all freeway.

Are there any good tips out there for getting the best fuel mileage?

I read in one of the other threads that there are secondary fuel injectors that kick in at around 3700 rpm. Is that true?

 

Yeah, I think it's actually 3,750 rpm. But with your planned driving scenario, don't get too hung up on that. I'm getting just under 20 mpg with mixed driving, and I just did a 560-mile Interstate run at 75-80 mph and averaged 22 mpg. If you can keep it under 75 mph in 6th gear, you might gain a couple of mpg at best. Why not experiment with a couple of tankfuls, one with sustained speed over 75 mph and one at just under 75 mph to see if maintaining the revs below 3,750 rpm really makes a significant difference. My guess is that the gain is not worth worrying about keeping the revs below a certain point. We'd be interested in the results if you do such an experiment.

 

I just did a 225 mile highway trip running around 74mph the whole time and got 23mpg. This car isn't bad on a trip when you just let it cruise, you just get bad mileage around town because you have the opportunity to open it up some at stop lights.

 

just tried 93 again and i got 215 and i filled up 12.5 my car has had its fair share of problems too.

 

Since a search of “gas mileage” returns 13 pages I can see why a new member would bypass all that info. Gas mileage has been discussed & discuss and discuss some more on this board. Bottom line is fuel economy sucks on this car, nothing you can do about it. 20 MPG is actually above normal and most members would love to get that. I too have a 6-speed and can get 20 if I shift like you. Problem is the 9,000-RPM redline entices you to drive hard and use more fuel. Count yourself lucky.

 

Yup, mileage has been discussed here many (ad infinitum) times before. they pop up in their own threads (like this), or can randomly breakout in any give thread.

but if you are getting 20mpg in town, you are definately getting more than most. it seems the board average is around 15-16mpg city, and i get in the 17s for city.

there's lots of things that can affect fuel economy...amount of weight in the car (driver, passenger, anything else), altitude, weather conditions, tire pressure, terrain, gas blends, traffic, etc...so its actually rather difficult to quantify.

I'm sure if i lived in florida, i'd get better mileage just because its flat, but i live in georgia, and its rather hilly here, the traffic is bad, and the lights aren't timed.

mechanically, the 2nd set of intake port opens at 3750rpm and the 3rd set opens at 6250 rpm, so the easiest way to keep mileage up is to keep it below 3750.

welcome to the board, and remember:
* don't rev over 3k until the engine is warmed up
* your gas mileage is going to suck
* shutting the engine off when its cold increases chances of flooding
* periodically get the revs above 8000 to clear out carbon build up
* the engine is designed to burn oil as it runs, so check your oil level regularly
* most importantly, have fun.

don't sweat the mileage too much (it is going to suck) because if you do, you won't be enjoying the car.

oh yeah, 6MT for me.

 

If you're getting 20mpg in town...then yeah, your driving sucks. That's not how you drive a car w/a rotary engine!

But from an economical/fuel efficient stand point, you're the man. I get 17 - 18 mpg using that method.

I'm curious... what RPM are you usually going into second at from first while you're driving your RX-8 like an old lady and shifting that soon?

 

I only hit 9,000 on the track and mine is fine. No real need to go that far over 8,500 power wise.

 

welcome and congrats
do a search please

 

What I haven't been able to find is an easily understood explanation of why the mileage sucks.

Please understand, I know it does. I'm not saying anything about that. I'm just curious as to what the technical reason is. With about 90% fewer moving parts, you'd think the thing would be better.

Is is simply down to the fact that the apex seals are not able to keep as tight a seal as a piston ring? Is that where the efficiency losses are?

Thanks

Hunter

 

I hate you guys...I stopped tracking my MPG but I was never even close to 20 in the city. I think I got 18 once on the highway.

 

the efficiency losses in the old 13b was partially due to valve timing and partially due to the long combustion chamber.

on the old 13b, the intake and exhaust ports were on the rotor housing, and by having them there the apex seal was the divider that kept intake and exhaust seperate...but it wasn't 100% effective (but what is?) and some unburned fuel would slip out through the exhaust.

this was addressed on the renesis by moving the ports to the side housing. by doing this the intake/exhaust "divider" became the side seal, which is better able to keep the two seperated and reduce, if not elimite unburned fuel slipping through.

next is the shape of the combustion chamber. it is fairly long, and at high rpms it become difficult for the fuel to have enough time to burn before getting exhausted.

i think that's a pretty good layman's explaination *nods to self*
but someone like rotarygod could explain in more detail (and possibly some areas that i missed).

 

As I understand it, it's not the sealing ability of the apex seals, it's the lousy thermal efficiency of the wankel design (and there's no way around it that anyone's found yet.)

It's lousy because of the large area the comustion charge has to do work over. All that wasted energy gets put out as heat, into the metal, into the water, into the oil..

If you think 16mpg is craptacular from a 1.3 liter 200-ish HP na wankel, what would you had thought of a 16mpg 1.3 liter 140 hp na wankel?

That was the NA 13B.. and 16 mpg was avg in the city for that motor..

Or how 'bout the 12A? 100-ish hp, and yup... same dismal gas mileage.

IIRC, the single-rotor, 80hp (I think?) NSU Ro-80 also got about the same..

All considered, I think 16 from the current 200+ motor is quite remarkable.

By the by, isn't 16~20 about right for most any 200+ horse motor? (variable displacement tricks like those in the modern hemi need not apply.)

The wankels are a *little* worse than a piston motor on gas, but face it.. if you're gonna make 200 hp, you're gonna move enough air, and have enough fuel, to supply that demand.. and that means, Power Costs.. How Much Do You Want?

All considered, I'll forsake the mileage, and enjoy the smmmmmooooth, progressive, controllable power of a rotary over most pistons.

The *only* thing that compares to these rotaries, imo, is a v-12... and that I can't afford, not anytime soon.. :D

 

i shall sum up all my thoughts about this right now....read his post ^^ :D

 

i stoped trackgin it long ago as well......when i started to average like 14-15 in the city ..adn 17 on highway....lol ohwell what can i say my baby likes to rev :D

 

Okay, thanks
the large combustion area helps explain things to me

Hunter

 

Whe does everyone get so upset when someone post a topic that has already been talked about. I believe that all there is to discuss about the car has most likely been brought up before so then why continue with the forum. The point I am trying to make is that there are always new members and people with new information and opinions. I still find it interesting to read about topics already discussed because there is usually fresh ideas and opinions.