2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

how to get 30+ mpg on a n/a rex

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Old Oct 11, 2005 | 08:51 PM
  #51  
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Originally Posted by SonicRaT
The Enzo gets 8/12
360 gets 11/16

Not too far off from what most of you FC guys get!
Pffff, I get 9/13 and make more HP than an Enzo. That cars for amateurs
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Old Oct 11, 2005 | 08:55 PM
  #52  
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Yah.. it has nothin on the 13B n/a!
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Old Oct 11, 2005 | 09:04 PM
  #53  
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i get 42 mpg...











































IN MY HONDA!
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Old Oct 11, 2005 | 09:10 PM
  #54  
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Way to break the forums with that picture >_<
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Old Oct 11, 2005 | 09:23 PM
  #55  
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I agree with Kevin here. I get around 25 driving very gingerly with the throttle not opening the secondary butterflies and keeping the rpm's at 3000 on highway.

Also, taller, skinnier tires would help. Proper tune-up, removing un-necessesary junk from inside of the car too.
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Old Oct 11, 2005 | 10:23 PM
  #56  
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Originally Posted by jono20
look at the price when they were first produced. noob. with inflation, wow
Yeah, $20K 15 years ago was like $100K today...
Oh wait, no, I actually understand how inflation works.
Do you?

Do you consider a brand new accord to be high end?
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Old Oct 11, 2005 | 11:33 PM
  #57  
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Always drive downhill.
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Old Oct 12, 2005 | 12:31 AM
  #58  
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Originally Posted by jono20
look at the price when they were first produced. noob. with inflation, wow
scathcart??? A noob??? I've heard it all now.
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Old Oct 12, 2005 | 12:38 AM
  #59  
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just sell it and get a moped
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Old Oct 12, 2005 | 12:42 AM
  #60  
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OK well can anyone explain why my 86 base was not getting any where near the mpg people are saying with similar mods? no cats, rb cat back, cone filter, and no a/c ps or airpump with the 5th and 6th ports activated by switch and left off for daily driving and a motor that had good compression and a wieght of only 2450lbs with light footed highway driving i might see 22-23 mpg but in my normal driving i'd see just under 20 even if i tried not to go above 3500 rpm
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Old Oct 12, 2005 | 12:57 AM
  #61  
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From: Kzoo, MI
90 glx with 85k miles, bone stock
700 miles all hwy, with a/c, nearly flat, kc, mo to michigan

26.5 mpg @ 70 mpg no cruise control, 50% a/c on. tires at 28 psi

premix with penzoil semi synthetic (walmart) 12 oz per fill of around 15 gallons.

u can get around 130 mpg from a regular car, can't remember where I read it, but all you have to do is speed up to 50 mph and shut the engine off and glide till if stops and keep repeating.

offcource I am JOKING pls do not try this as it is very dangerous, yada yada...
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Old Oct 12, 2005 | 01:02 AM
  #62  
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Originally Posted by RETed
You're not going to get over 30mpg unless you want to drive only on the freeways.
Is that what you're doing???

Getting 35mpg (or over that) is next to impossible, as Rotary Resurrection said.

If you want good gas mileage, get another car, period.


-Ted
Exactly, RX7's were built for fun, not economy, most of us who care enough about gas mileage or just cant afford it drive other cars.

I drive city so i get 17-18 mpg all the time, but i love driving my seven so much it's kind of like give some to get some.
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Old Oct 12, 2005 | 01:10 AM
  #63  
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Originally Posted by jono20
look at the price when they were first produced. noob. with inflation, wow

Sorry man but unless FC's were like 60 grand when they were new they arent a 'high end' sports car. 160hp and 140lbs tq (roughly FWHP) isnt high end either. no doubt they are alot of fun, but, with a 15-20 year old car, its pretty much what you make of it, and if its stock, n/a atleast, its not excatly fast, but I look at MY fc and see a beautiful machine, not trying to offend, its just facts
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Old Oct 12, 2005 | 03:12 AM
  #64  
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Originally Posted by totallimmortal
OK well can anyone explain why my 86 base was not getting any where near the mpg people are saying with similar mods? no cats, rb cat back, cone filter, and no a/c ps or airpump with the 5th and 6th ports activated by switch and left off for daily driving and a motor that had good compression and a wieght of only 2450lbs with light footed highway driving i might see 22-23 mpg but in my normal driving i'd see just under 20 even if i tried not to go above 3500 rpm
5th and 6th ports activated by switch?
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Old Oct 12, 2005 | 04:32 AM
  #65  
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alright alright, not HIGH end, but still, im sure when people saw an RX-7 driving past, they looked. (my definition of high end I suppose)
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Old Oct 12, 2005 | 08:53 AM
  #66  
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OK, we're getting significantly off topic here. Bring it back, or the thread ends...
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Old Oct 12, 2005 | 09:12 AM
  #67  
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I look at the big picture - dollars per year.
That includes the car, maintenance parts & supplies (gas), and insurance.
I check MPG only to spot tuning/maintenance problems.

Currently I get 16-17 MPG around town.
Also I have currently pulled back the boost & timing for 87 octane.

For now the RX-7 is perfect.
In 4 years, who knows..
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Old Oct 12, 2005 | 09:45 AM
  #68  
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even though the car is not 'made for fuel economy' doesn't mean some of us would rather get 15 mpg when others claim 30 mpg. and it doesn't cost so much. so helping any is better than just saying you can't do it, nothing can ever be made perfect but supposedely can always be made better. I thought of a rotary powered vehicle that would probably be fuel efficient. I have an 83' RX-7 1st gen with a 12a and i have a couple extra S4 N/A 13b's. I think a combination like that controlled by a megasquirt n' spark (which is only like $350?) would probably make atleast 30 mpg, i might do that like next year. because the fb is lighter and would benefit from the extra power anyways. this thread makes me want to sell my turbo II, but seeing as the engine is blown right now im not spending no gas on that car. we all should try and do something about these gas prices anyways, not i don't wanna make this into a lounge thread but these oil wars should stop soon around the world.
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Old Oct 12, 2005 | 04:54 PM
  #69  
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Originally Posted by totallimmortal
OK well can anyone explain why my 86 base was not getting any where near the mpg people are saying with similar mods? no cats, rb cat back, cone filter, and no a/c ps or airpump with the 5th and 6th ports activated by switch and left off for daily driving and a motor that had good compression and a wieght of only 2450lbs with light footed highway driving i might see 22-23 mpg but in my normal driving i'd see just under 20 even if i tried not to go above 3500 rpm
I will try to help you on this one, but first let me explain my scenerio. The car: 89 GTU, 5 speed. 50,000 mile Mazda series 4 remanufactured shortblock. All series 5 externals were on my car. Now onto modifications, cheapie cone filter. Hollowed catalytic converters, High flow stock type mufflers. I can't remember what brand. Nearly flat highway driving at 3000 rpm which to me is about 70 mph. I always kept the throttle closed to the point where the secondary butterflies were closed. (I could feel the slightest resistance in the throttle when the secondary plates would open. Fairly fresh, proper viscosity fluids in the car, Engine oil, castrol 20w50. Premixing at a ratio of 200:1 while still using the stock MOP. Tires: P215/60/R15 mounted on "Bologna slicers" inflated to 38 PSI cold. I would get 25 MPG. The car was in excellent tune as well. I had 125 psi compression per face.

totalimmortal, I think were are prettymuch on the same page here. The figures you describe are not out of line with my figures. As you can see, I tried to get the milage to be that high, which isn't too bad. I personally don't think a sports car is designed to be as fuel efficient as economy cars. It's built for performance, not economy. Add to that, the rotary engine weren't exactly the most efficient designs at the time, I think these are pretty respectable numbeers. Now, when I go driving on the "Twisties" I notice my fuel economy drops to about 17 or so. I also notice that the cooler the weather is, my economy drops respectively. It's understandable since the fuel-air charge is more dense when the air is cooler. I have considered an EGT and a SAFC for economy, but I hardly ever drive the car, so it's not economically feasible at the time. Also I thought the economy of these cars were great compared to my old truck which I sold this spring. That old beast would get 15 mpg at best, downhill with the wind at your back. Drive 150 miles a day with that milage and see how happy you are. Then get a car capable of 25 mpg. Now I bought my wife a KIA Rio that gets 35+ mpg. not too bad. It would do better with a lower 5th gear.

lesson here, appreciate it if you get 17+mpg. It could be worse. Of course you could also try to use the "Fish carburetor" or "Pogue carb?" The claimed way back super fuel economy. The patents are out there, just try things and see It seems we have too many complainers and not enough invenors/tinkerers. If you don't like paying $3.00 or more per gallon of fuel, then do somthing about it. Invent a method of better economy, get a more efficient car, carpool, or don't drive.
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Old Oct 12, 2005 | 06:29 PM
  #70  
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Speed: 80 mph for 120 miles each day commute
Fuel Economy: 48.6 mpg for last tank that got me 750 miles before I had to refuel.

Oopps, sorry I thought this was the tdiclub.com forum

Seriously, the lesson here is that a rotary engine is not an economy car and if fuel economy is a main concern, you may want to consider another ride.

I love my vert, but just taking it out for a summer's night drive to the nearest sonic costs me about 7 bucks in gas. It sucks living in the boonies.
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Old Oct 12, 2005 | 09:44 PM
  #71  
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I feel the same way Sureshot does. I look at the entire picture.

The way i see it is my car is paid for, i run liability and thats it. Now that all the maintanance is done its been trouble free( knock on wood) and low cost to keep up. It doesnt need some pricey oil for oil changes like my vette did. It doesnt like premium gas like my vette did. And insurance is cheap, unlike my vette was. Ive got mine getting around 20mpg in mixed driving, around 25mpg on the open road and this is all with me being civil behind the wheel so im happy with those numbers. I will probably buy another one soon and get a coupe just because its so cheap for what you get and upkeep isnt too bad for the most part so i dont mind the mediocre fuel economy. I say this until it hits something like 4 bucks a gallon and then i will be riding my bicycle everywhere. I was going to sell my car a short while ago and if someone came up to me id still be inclined to do it. But in reality its too cheap to get rid of and start over with something else.
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Old Oct 30, 2005 | 11:56 AM
  #72  
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i don't have a problem with the gas mileage i get, for me the car is for fun it's not a daily driver and thats fine but i just am curious as to why people with almost the same mods and car but usually in a slightly heavier model are getting 10 mpg more than me or roughly 50% better fuel economy. I understand it wasn'ted designed for fuel economy and i really don't mind i'f mine ever goes up i just finr it odd that it varries by so much between similar cars
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Old Oct 30, 2005 | 12:18 PM
  #73  
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I use my RX-7 as my DD, easily around 200-300miles per week, sometimes more. I usually get around 20-15 mpg combined driving, city, and highway, and that includes stomping it every once ina while. If I do strictly highway driving, I get around 25-31ish.

The Car is an 87 Base model, with some upgrades. Custom itake box w/ K&N filter, header, 2.5" Highflow cat, 2.5" piping back to some hollow "Race Series" magnaflow mufflers. I also have a 4.1 LSD from a GXL in there instead of the 3.9. It's got a rebuilt tranny, new clutch, new clutch hydraulics, new tranny mount, and new diff mounts, New struts and springs, new polyurethane bushings, Light wheels with 205/75/14 tires @35 PSI

183k- stock engine
I don't think my 5th and 6th ports work though, But i still beat the V6 mustangs with full exhaust and intake, and I whoop the **** out of my friend whos got an s5 vert with a 10,000 mile rebuild.
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Old Oct 30, 2005 | 06:03 PM
  #74  
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haha
wow, I get can get about 11mpg if I try in my 89 NA, city, highway, it doesn't matter
I think my main problem is that when I go to flog it, my 5th & 6th ports dont open, I also have leaky injectors and fuel filters as old as the car

however untill I took the time to find out with my MPG was and how much better it could be I didn't really care because it's fun car to drive
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Old Oct 30, 2005 | 11:11 PM
  #75  
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The major value of fuel economy numbers is a determination of "Is my car running properly?"

11mpg regardless of city/highway speaks to either a lead foot or some fairly major problems.

13-17mpg city, 18-25mpg highway would tend to indicate a car running fairly well (hopefully towards the higher end of the highway range).

30mpg is doable, but only with a standalone, emissions removal (so you don't melt the cats), good tuning, and some intake/exhaust work. It's more a side effect of stuff done for other reasons, not a reasonable goal in and of itsself (the cost of the stuff needed to do it won't pay for itsself in gas in any reasonable time).

Much above 30mpg is only going to be doable with a piston engine swap (and probably *not* a big V8).

-=Russ=-
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