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improve your mileage?

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Old 01-22-2005, 02:48 AM
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improve your mileage?

ok, this is not a gripe about the bad mileage. i've accepted my 8's crappy gas mileage, but is there anything i can do to at least improve my 15 mpg?
Old 01-22-2005, 02:57 AM
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Shift at or below 3500 RPM. Take it easy, drive like a grandpa. Take all the junk out of the trunk.
Old 01-22-2005, 03:17 AM
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As Shaolin said, lose some weight.
Old 01-22-2005, 04:15 AM
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Going with lower octane gas might help as well. I recently made the switch from 92 to 89 just to experiment, and it seems to do about 1mpg better...my first time I used it, it was mixed with 1/4th of the tank filled with 92, but it already made a slight difference...instead of my usual 14.7-9 or so, it jumped to 15.3, with hard driving. My current tank is all 89, but I'm not so sure I'm going to use it again, because there is a definite lack of throttle response compared to using 92. Whereas before I'd feel the power start surging once I got the rpms over 4k and stepped on the gas harder, now even stepping on the gas harder over 4k, the car just doesn't really have that surge.
Old 01-22-2005, 07:50 AM
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Experiment with different brands of gas too, several tanks in a row of the same brand to get an average. So far I've done Citgo 93 & Exxon 93; while the Exxon feels smoother, it seems to be getting ~1 mpg less. Citgo avg 16.5, Exxon 15.5, combination of city & highway about 2 to 1.

Something else we need to take into account while comparing mileage is terrain. This part of Virginia has lots of low rolling hills, so we'll get worse gas mileage than people who live in flat areas.
Old 01-22-2005, 10:13 AM
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Originally Posted by mdroz8
ok, this is not a gripe about the bad mileage. i've accepted my 8's crappy gas mileage, but is there anything i can do to at least improve my 15 mpg?
Don't worry, be happy. My last measurement was 9.01 mi/US gallon
Old 01-22-2005, 10:19 AM
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sell it and buy a geo metro?
Old 01-22-2005, 10:37 AM
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I get 16mpg around town shifting around 5500. I have gotten as low as 13mpg, beating the crap out of it. I just got 20mpg driving to NYC and back (from Phila) with the cruise at 85-90.

Recent comparo: I would get ~18 around town in my 24V VR6 Jetta and ~22 on the highway.

I just wish we had a bigger gas tank. The G35 coupe has a 20 gallon tank! I feel for the folks getting 10mpg.

Last edited by Malloy; 01-22-2005 at 10:39 AM.
Old 01-22-2005, 10:40 AM
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Does junk in the trunk really affect gas mileage?
Old 01-22-2005, 10:40 AM
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Originally Posted by mdroz8
ok, this is not a gripe about the bad mileage. i've accepted my 8's crappy gas mileage, but is there anything i can do to at least improve my 15 mpg?
Yes, I think so. I've found, for example, that my mileage varies directly with the amount of time, not miles, I spend in "stop 'n go" traffic. It may not be possible for you to avoid such conditions, but I've found if I avoid a particular five mile stretch of my daily commute where the average speed in 4-5 mph, my mileage is substantially improved.

Likewise, when I'm on the freeway in light traffic, I typically set my cruise control to 70 mph which keeps my revs below the magic 3750 rpm. Is that "granny driving?" Perhaps. But frankly, I don't find that cruising at 80-90+ mph is far more thrilling than cruising at 70 mph. (In fact, the sensation is virtually identical.) And it reduces the likelihood of picking up a ticket that will increase my insurance premiums and get me an additional ticket for driving without a front plate.

Finally, I don't try to win stoplight derbies in my RX-8. The car wasn't designed to do so and the skill it requires from a driver consists almost exclusively of how hard/fast you can stomp the accellerator. (Not an interesting test of driver skill, imo.)

For me, the thrill of the RX-8 is taking it out on twisty backroads (which are fortunately nearby) where I can drive it like the sports car it was designed to be. If your thrills consist of (a) winning stoplight drag races or (b) dropping the hammer on long straight freeways there are far better vehicles.

Following these guidelines, I've consistently gotten mileage between 18 and 20 mpg. If you're getting 15 mpg or less with the same behavior, I'd say there's something wrong with your car. Just IMO.
Old 01-22-2005, 03:30 PM
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I just switched from 89 to 93 and have noticed a decent drop in gas mileage. However, I have also noticed a bump in performance. For me, I'd rather realize the full potential of the engine and shell out a couple more bucks per fill-up.
Old 01-22-2005, 05:29 PM
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If you can be comfortable w/o A/C you will find a slight increase in mpg. I usually drive with the window or sunroof open.

- Irish
Old 01-22-2005, 08:39 PM
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Originally Posted by irish8
If you can be comfortable w/o A/C you will find a slight increase in mpg. I usually drive with the window or sunroof open.

- Irish
A/C, were in the dead of winter in 2/3 of the country.

I believe stop & go traffic definately makes a significant difference, also warming up the car. I don't drive my 8 in the winter, but I do start it up and run it for about 1/2 hr each week. When I took it out last week for some excersise and filled up the tank, I think I calculated 10-12 mpg. I usually average 19. So just diling the car used an enormous amount of gas.
Old 01-22-2005, 08:49 PM
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Originally Posted by r8ped8
sell it and buy a geo metro?
Yes!
Old 01-22-2005, 09:00 PM
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Originally Posted by salituro64
A/C, were in the dead of winter in 2/3 of the country.
....and your point is? It's not winter all the time!!

- Irish
Old 01-22-2005, 09:51 PM
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Originally Posted by V_for_velocity
Don't worry, be happy. My last measurement was 9.01 mi/US gallon
Woah, holy bat-poop batman... That is bad. Compared to that my 14 mpg is a God-send...
Old 01-22-2005, 09:59 PM
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My Best was 18 mpg , and for the life of me LOL I cant remember how I did it . I drive intown totally , maybe a strecth of highway for a couple of miles . The week I got the 18 I cut down the warm up time , I use to warm it till the gauge was straight up , so I started driving when it moved up to the "c" . Since that magical week , I have done the same , and back down to 15 mpg . I do know I shifted at a lot higher RPM . I tried the under 3750 rule , and it made no difference that I could . I dont drive like I stole it , but I dont putt putt either. I dont have 93 or 92 octane here , V-Power here is 90 octane , plus I'm 3500 feet above sea level , which I think has some to do with it .
Old 01-22-2005, 10:02 PM
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Best: 25.76, Interstate, 60 mph steady
Old 01-22-2005, 10:12 PM
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When I was in Auto Tech school, the instructor told us that one loses 1 mpg for every 100 lbs they carry extra in the car.
Old 01-23-2005, 08:59 AM
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Originally Posted by nomopistons
When I was in Auto Tech school, the instructor told us that one loses 1 mpg for every 100 lbs they carry extra in the car.
Sounds about right. A strong argument for (a) Atkins and (b) smaller g/f's or SO's.
Old 01-23-2005, 09:05 AM
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Originally Posted by irish8
....and your point is? It's not winter all the time!!

- Irish
It's also not a good idea to leave your A/C off for such a long period (ie. entire winter season).
Old 01-23-2005, 11:28 AM
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(Regarding my report of 9.1 mpg):

Originally Posted by Texas 8
Woah, holy bat-poop batman... That is bad. Compared to that my 14 mpg is a God-send...
I'm attributing it to extreme cold since Xmas, when I bought her, all in-town driving, the hole in the ozone layer, the Jayhawks' loss to Villanova, and maybe, just maybe, Donald Rumsfeld has something to do with it.
Old 01-23-2005, 11:37 AM
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Well are factors ive seen for lower milege

in the summer i usually avg 14-16 mpg

idling, in the winter since i dont really drive the 8 much i see about 10 mpg since most of the gas is wasted in idling

stop n go traffic, the times when i grow some ***** and decide to take the 8 into the city (NYC) i will see about 12-13 mpg

and most importantly, I read a thread that said the second port opens around 2700 rpms. This limits you to 57mph in 6th gear. I tried shiftin before 2700 and i got 20+ mpg But then i had geo metros blazing by me at 80 mph and still getting 25+ mpg
Old 01-23-2005, 02:00 PM
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I get 17mpg around town if I dont get on it too much and have got 19mpg if I take it easier. I did two tanks at 65mph and got 27.5mpg. I did one tank in the slow lane with the trucks 55-60mph and got 29.5mpg. This is my seventh rotary and the best yet! I cant drive 55, so this is just to see what it could really do if that was most imporant to me. This rotary has twice the hp of my first and more than 25% better gas mileage. I wish more people were developing this engine think where it would be if 50% of car makers were working on it!

Last edited by Old Rotor; 01-23-2005 at 02:13 PM. Reason: add info


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