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Better MPG?

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Old 03-28-2010, 05:13 PM
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Use the paddles and never shift above 3K rpm. (Causes more expensive long term repairs then saves gas IMO)

Avoid using the brakes whenever possible by anticipating upcoming traffic lights, stop signs, traffic and letting off the gas and downshifting ahead of time. Most late model cars, rx-8 included, will stop using gas while coasting in gear at sufficient RPM. (I do this all the time)

Only drive downhill.

Only drive on highways.


Swap the auto for an MT. Torque converters suck.

Buy a Tesla Roadster. (Or a Hammerhead i Eaglethrust)
Old 03-28-2010, 06:10 PM
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AB

Originally Posted by Loki
So far I've found, by the way, that grannying it gets you worse MPG than being moderately aggressive.
Oddly, I've found this too...any idea where the sweetspot is?
Old 03-28-2010, 07:23 PM
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I'm still trying to figure out how your old contour got 20, those things are rated at mid to high 20's.
Old 03-28-2010, 09:48 PM
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Bumper-to-bumper traffic will do that, along with having your car in a not-so-great state of tune. Maybe having a/c on a lot of the time, too? All that could easily drop EPA city # from 25 to realistic 20.
Old 03-28-2010, 10:24 PM
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Originally Posted by jrbirch
Oddly, I've found this too...any idea where the sweetspot is?

I've found that on the highway you want to be either at 60mph(100kph) or ~80(130kph). Those get you 22-23mpg. At 70(115-120) you get ~19. I need to retest this though, haven't had enough long-range drives on different settings to make this a certainty, it's just observations so far..

As for city, I used to granny it shifting at 3-4 and cruising at 2-3 (bad idea anyway), and that got me nowhere as far as better mileage, so now I shift at 5-6 and cruise at 3-4, but what I think is more important than that is the throttle position. I get up to cruising speed quickly (say 50% throttle) then coast or cruise steadily from there.

It almost feels to me like 3700rpm cruise is some kind of low point in fuel economy, you want to be above or below it, but below isn't super practical.

BTW, as far as using fuel while coasting.. I think on most fuel injected cars this side of 1996 the injectors are off while coasting (with a manual trans, at least), and the engine is just pumping air while the car's motion keeps it turning.
Old 03-29-2010, 04:05 AM
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Originally Posted by Socket7
Swap the auto for an MT. Torque converters suck.
Torque converters suck less in the last 20 years or so, due to lock-up technology. Also, in the case of the RX-8, the A/T is geared MUCH higher cruising in top gear (about 30 mph / 1000 rpm) than the M/T (about 20 mph / 1000 rpm). That's why the A/T EPA mileage rating is higher than the M/T.

All random complaining aside, I think monitoring fuel consumption trends is an important tool to follow the motor's overall health and state-of-tune. When the mileage starts trending downward, it's time to determine the cause before bigger problems arise.
Old 03-29-2010, 11:56 AM
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Originally Posted by Loki
I've found that on the highway you want to be either at 60mph(100kph) or ~80(130kph). Those get you 22-23mpg. At 70(115-120) you get ~19. I need to retest this though, haven't had enough long-range drives on different settings to make this a certainty, it's just observations so far..

As for city, I used to granny it shifting at 3-4 and cruising at 2-3 (bad idea anyway), and that got me nowhere as far as better mileage, so now I shift at 5-6 and cruise at 3-4, but what I think is more important than that is the throttle position. I get up to cruising speed quickly (say 50% throttle) then coast or cruise steadily from there.

It almost feels to me like 3700rpm cruise is some kind of low point in fuel economy, you want to be above or below it, but below isn't super practical.

BTW, as far as using fuel while coasting.. I think on most fuel injected cars this side of 1996 the injectors are off while coasting (with a manual trans, at least), and the engine is just pumping air while the car's motion keeps it turning.
That jives with what my instincts are telling me too...

I wonder about highway cruising in 5th rather then 6th? Could it have to do with the lower power at lower revs?

Is fuel consumption as tightly tied to engine rpm in a rotary the same way that it is in a conventional engine? One of the ways that a conventional engine gets better fuel economy is that it shuts off fuel to some of the pistons, essentially turning a V8 into a V2. I don't suppose that trick would work in a rotary. *grin*
Old 03-29-2010, 12:01 PM
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Originally Posted by MarcMiller
i go through gas 3 times a week on driving normally...i cant afford that.
This is where i stopped reading.
Old 03-29-2010, 01:21 PM
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Originally Posted by mmGilbert
This is where i stopped reading.
your fault?
Old 03-29-2010, 01:24 PM
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Well, if you seriously bought this car and didn't plan on bad gas mileage, shame on you. If you wanted better fuel economy, buy a different car.
Old 03-29-2010, 01:28 PM
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Originally Posted by mmGilbert
Well, if you seriously bought this car and didn't plan on bad gas mileage, shame on you. If you wanted better fuel economy, buy a different car.
When did i say i didn't plan on bad gas mileage.
and i never said anything about finding out about the gas recently either....i bought the car knowing it had the gas mileage it did....i'm just trying to FIND WAYS to make it a little better.


Being such a common issue you would think people found a few ways to make it better.


Read before you say ****.
Old 03-29-2010, 01:30 PM
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So you bought a car KNOWING that you couldn't afford gas for it. It baffles me.
Old 03-29-2010, 01:34 PM
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Originally Posted by mmGilbert
So you bought a car KNOWING that you couldn't afford gas for it. It baffles me.
I can afford the gas for it...it just goes through it fast.
NOTICE ME ASKING WAYS TO INCREASE MPG?

im not on here complaining or anything im just asking ways to increase it...if there are any

so shut up...everyone on this forum does nothing but bag on peoples questions.
some people are telling me ways when other people like you just see something and talk ****.
Old 03-29-2010, 01:38 PM
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A better final gear for highway would help (Series II) but I suspect you're in traffic often so a tranny swap won't do you any good.

Take your MAF sensor out and clean it, disconnect your neg batt. cable for 15 minutes then reconnect to reset the fuel trim. That might help somewhat.

If your car has a lot of miles on it say 40k+, get new plugs and possibly new coils as a last resort as someone mentioned earlier.

Last edited by Vlaze; 03-29-2010 at 01:41 PM.
Old 03-29-2010, 01:40 PM
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Originally Posted by MarcMiller
I can afford the gas for it...it just goes through it fast.
NOTICE ME ASKING WAYS TO INCREASE MPG?

im not on here complaining or anything im just asking ways to increase it...if there are any

so shut up...everyone on this forum does nothing but bag on peoples questions.
some people are telling me ways when other people like you just see something and talk ****.
Calm down. I'm not talking ****. You clearly said you cant afford gas, so I simply stated this car is probably not for you.
Old 03-29-2010, 01:44 PM
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Originally Posted by Vlaze
A better final gear for highway would help (Series II) but I suspect you're in traffic often so a tranny swap won't do you any good.

Take your MAF sensor out and clean it, disconnect your neg batt. cable for 15 minutes then reconnect to reset the fuel trim. That might help somewhat.

If your car has a lot of miles on it say 40k+, get new plugs and possibly new coils as a last resort as someone mentioned earlier.
My engine only has 36k miles...body has 75k.

Originally Posted by mmGilbert
Calm down. I'm not talking ****. You clearly said you cant afford gas, so I simply stated this car is probably not for you.

I honestly dont think im getting 18mpg or even close...on a full tank of gas i cant get over 150 miles.

How can i do a test to see how many miles i get per gallon? Im actually about to fill up soon so whats the best way.


I was reading about an M flash that helped people with gas milage?
How can i tell if all my recalls are up to date?
Old 03-29-2010, 01:48 PM
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If your seriously getting 150 miles on a full tank, then your hardly pushing 10mpg. I can get around 250 miles on a tank. Which is still around 15mpg.
Old 03-29-2010, 01:50 PM
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2 weeks One fill up

secrets to my success bellow!!!!


step 1 - get on plane
step 2 - drive to gas station when flight lands

bam!
Old 03-29-2010, 01:53 PM
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Originally Posted by mmGilbert
If your seriously getting 150 miles on a full tank, then your hardly pushing 10mpg. I can get around 250 miles on a tank. Which is still around 15mpg.
Saying on a "full tank" is different for everyone since you can't literally say that unless you run it dead on empty.

That being said, everytime I fill up it's around 13-14 gals used, never close to the 15.9 even when I've filled up on E before.

I get around 240-250 in the city netting 18mpg city wise and around 280-290 on the highway netting 21.
Old 03-29-2010, 02:00 PM
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Thats true. When I did my test, I think it only took like 14 gallons. Which would bring my mpg up to 17. So when you check your mpg, make sure you divide by the amount you put in the tank, not the tank size.
Old 03-29-2010, 02:39 PM
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Take the money you would use for expensive mods (CAI, exhaust, Access Port, anything else) thinking you'll get better mileage, and buy more gas...or waste the money on mods, then get the same mileage as before, but now you're broke buying mods and can't buy more gas. Simple! Here's how it works...

At $3 gal and 18mpg each mile costs $.17 ... so don't buy some CAI @$400 and you can go an extra 2353 miles @18mpg. Some $600 exhaust - extra 3529 miles, and so forth. See how quickly the savings add up?
Old 03-29-2010, 03:10 PM
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If it it's really bad, get your car checked out for bad coilpacks, spark plugs and cat . Any one of those would give you bad fuel economy.
Old 03-29-2010, 03:12 PM
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Originally Posted by Socket7

Only drive downhill.
This is a great tip! The only problem is once you hit sea level youre screwed haha. Hey at least you'll probably end up at the beach
Old 03-29-2010, 03:29 PM
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Affter removing my VFAD, adding K&N drop in and Flow Master exhaust, as well as premixing and resteting my ECU I am hitting city and highway combo at 22mpg. thats also going no slower than 70 on the highway (04 MT 70,000)
Old 03-29-2010, 04:52 PM
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Originally Posted by Spin9k
Take the money you would use for expensive mods (CAI, exhaust, Access Port, anything else) thinking you'll get better mileage, and buy more gas...or waste the money on mods, then get the same mileage as before, but now you're broke buying mods and can't buy more gas. Simple! Here's how it works...

At $3 gal and 18mpg each mile costs $.17 ... so don't buy some CAI @$400 and you can go an extra 2353 miles @18mpg. Some $600 exhaust - extra 3529 miles, and so forth. See how quickly the savings add up?
But my 4,705 mile exhaust sounds sooooo good.


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