better gas mileage?

[Clip]

hey all, searched and couldn't find a complete answer to what i was looking for.

is there any drastic way to increase gas mileage (beyond cleaning the fuel system/driving it easier) like shutting down a few cylinders while cruising or even switching fuels?

how hard is it to switch to propane, what kind of mileage comes from a gallon of propane compared to a gallon of gas?

i know e85 isn't too hard to switch to, just replace the fuel lines and retune for 85% ethanol.

 

[charlesshen]

hey all, searched and couldn't find a complete answer to what i was looking for.

is there any drastic way to increase gas mileage (beyond cleaning the fuel system/driving it easier) like shutting down a few cylinders while cruising or even switching fuels?

how hard is it to switch to propane, what kind of mileage comes from a gallon of propane compared to a gallon of gas?

i know e85 isn't too hard to switch to, just replace the fuel lines and retune for 85% ethanol.

E85 is worse on mileage and put out less power and as far as propane its got power and its cheap but i dont think kits exist for our cars

 

[Clip]

E85 is worse on mileage and put out less power and as far as propane its got power and its cheap but i dont think kits exist for our cars

i know that e85 is worse, but if i could find a source cheaper than gas i'll take it. i know ij made a kit for his supra, but it was all handmade.

 

[jetjock]

You can run much leaner than stoich as long as it's in steady state cruise. You can do that all the way up to about 75% power, which is more than you'll ever need going down a relatively flat highway. Course, knowing how to technically accomplish that is another story.

 

[Clip]

You can run much leaner than stoich as long as it's in steady state cruise. You can do that all the way up to about 75% power, which is more than you'll ever need going down a relatively flat highway. Course, knowing how to technically accomplish that is another story.

have any links so i can learn about the other story? i've found a few, didnt know if you had any choice links.

i doubt that a piggyback fuel controller like the safc could give the range control what i'd need it to, and if it did i guess need to use a wideband

 

[suprarx7nut]

Would you really spend all that time/energy/money to simply save a few dollars on gas?

If you get an extra 5 mpg that doesn't seem to offset the cost of a piggyback. Unless you already have one...

 

[Facime]

so the question is how to get more milage out of your supra?


buy a Honda?



but seriously, if your supra is your DD, and you are complaining about fuel costs...then a supra probably shoulndt be your DD. You could always just drive less.

 

[Clip]

so the question is how to get more milage out of your supra?


buy a Honda?



but seriously, if your supra is your DD, and you are complaining about fuel costs...then a supra probably shoulndt be your DD. You could always just drive less.

questions:

what are the mileage increases from switching to alternate fuels like CNG/LPG, is the cost feasible?
are there other options to switching fuels, such as running on fewer cylinders or running less rich like JJ suggested?


and i didn't think i was complaining, just looking for anyone with ideas on how to save a bit of gas (i wouldn't say it's unreasonable with prices rising like they are)

as for the "buy a honda" advice: got my eyes on an 86 mr2, my gf's gets great mileage, i figure it's got potential

Would you really spend all that time/energy/money to simply save a few dollars on gas?

If you get an extra 5 mpg that doesn't seem to offset the cost of a piggyback. Unless you already have one...

good point. i wouldn't mind spending time and energy working on something like this to get a sense of self-accomplishment and maybe save a few dollars on gas, i find it fun.

and you're right, it wouldn't necessarily offset the cost unless i could find a good deal on a piggyback.

 

[sethron71]

If you have read IJ posts about his attempts to switch I don't think you will be doing it any time soon. He is a very very smart man and has spend god knows how many hours attempting this and still hasn't got it under control. His last attempt was a huge leap but he is going to back to petrol for now.

If you have a piggy back you can lean it out but still has to be tuned proper for boost. Also how you drive it makes a huge difference. Stay out of boost and be gentle, avoid city driving if possible. My blue supra got 22-26mpg on the freeway when I wasn't boosting all around. But more like 18mpg when I was and at 420rwhp! A good tune makes a world of difference!

HTH,
Seth

 

[Facime]

well I inferred that you were complaining about the gas prices and cost of driving the Supra from the question. I just took it one step further.

There are lots of little things you can do to increase mileage. Properly inflated tires, a good tune, soft pedaling, reducing weight etc are low cost ways to improve your milage, but they wont add up to much. Switching to alternative fuels have one big pitfall as ^^Nut said, the cost of making the change doesnt outweigh the savings for a VERY long time. $1000 (just a round figure pulled out of the air) invested to changing over goes a long way towards fuel costs.

Its the same arguement against hybrid vehicles that cost so much more than their counterparts, the savings in fuel is offset by the cost of the technology. It can take years to pay off. You would probably do just as well to ride a bike for short trips, take the bus once a week to work, and avoid getting into boost as much as possible.


I guess I just dont understand why someone that owns a Supra would ask how to reduce fuel cost. Its like buying a 10,000sq/ft home then asking "how do I save on my heating bill"

 

[Clip]

I guess I just dont understand why someone that owns a Supra would ask how to reduce fuel cost. Its like buying a 10,000sq/ft home then asking "how do I save on my heating bill"

thanks for the tips
i suppose i would feel more foolish to ask the mileage question if i had recently bought a supra at today's gas prices, rather than 3-4 years ago.

i had also hoped to get a few links from this thread that would direct me towards CNG/LPG conversions and other options that i could also direct to a few other projects (vw buggy/sandrail and an old '41 truck).

 

[jetjock]

I gotta agree with Weezl. You want to play you have to pay. Frankly, if you want better fuel economy do everything he said and drive as if there's an egg between your foot and the pedal. Not much fun but it works.

That said there are people here running lean. Iirc that's one of the benefits of using a MaftPro. You'd have to do a lot of steady state driving for it to pay off though. Say long commutes on the highway.

 

[Clip]

I gotta agree with Weezl. You want to play you have to pay.

very true, just trying to get through my job this summer and school next year to get a better paying internship thanks for the help

 

[CyFi6]

Im pretty sure you would have to do more than just shut cylinders off to increase your mileage, it may even hurt it from the constant compression and friction. In the gm motors where they disable cylinders, they actually stop the valves from opening, so as one piston on one side of the engine is compressing the air in the cylinder another piston on the other side has low pressure in the cylinder, which counteract each other.

 

[Clip]

Im pretty sure you would have to do more than just shut cylinders off to increase your mileage, it may even hurt it from the constant compression and friction. In the gm motors where they disable cylinders, they actually stop the valves from opening, so as one piston on one side of the engine is compressing the air in the cylinder another piston on the other side has low pressure in the cylinder, which counteract each other.

that and mazda's SISS is pretty smart too.

http://www.thecarconnection.com/Aut.../Mazda_Zoom-Zoom_Going_Green.S196.A13568.html

 

[sluggo42]

You buy your wife a Prius that gets 45 MPG, then average the two.
Prius, 45
Supra 17
= 62
Divide by 2

I get 31 MPG!!

Problem solved:icon_bigg

 

[tlo86]

dont daily drive your supra thats how you get better mileage. ive filled up twice in 6 months

 

[steveyblack]

I gotta agree with Weezl. You want to play you have to pay. Frankly, if you want better fuel economy do everything he said and drive as if there's an egg between your foot and the pedal. Not much fun but it works.

That said there are people here running lean. Iirc that's one of the benefits of using a MaftPro. You'd have to do a lot of steady state driving for it to pay off though. Say long commutes on the highway.

said it perfectly...

if you still want a supra, get a NA...I get from 20-25 MPG, and thats with some pulls and a little heavy foot...

 

[SupraOfDoom]

Geo Metro: 40-58 MPG. Used Cost: $400-1200. /End

 

[AFQC]

My last ride was an ’04 5.4L F-150 that would get 14 mpg on the highway and about 10 in the city. Before I had a useful range of about 320 miles on a 26 gallon tank and now I can do the same on 18.5. When I bought my Supra it was incorrectly timed, had a clogged cat, sketchy ignition and a fouled O2 sensor that got maybe 16 mpg. After fixing all that stuff I am getting about 26 mpg on the highway and about 19-20 city. It still makes me smile when I only see a $50 tank rather than the $80-90 I was seeing before.