A Question about the "A-Series" Motors and MPG's

[emmahumpfritter]

Based on this list:

http://en.wikipedia.org/wiki/Toyota_A_engine

Which motor (that is available to the US) has the potential to get the highest MPG's in a tercel 4wd wagon.

I don't care one bit about having more power (the stock, tired 3ac actually has more than enough for my slow, explorative needs) I'm hoping to build a 4wd tercel version of this:

http://www.flickr.com/photos/40581861@N ... otostream/

Insulated, removed side windows, roof rack, basic adventure mobile amin's.

I would love to reach 40MPG somehow on the freeway and driving for max-MPG's

Is the 1.5L VVT-i even a realistic option for swap? I do have access to one in a wrecked Echo I know of.

Thanks,
Brenton

[keith]

Is the 1.5L VVT-i even a realistic option for swap? I do have access to one in a wrecked Echo I know of.

Thanks,
Brenton

Everyone here is hoping someone will try and see.

[Petros]

The max economy will come from a more modern EFI design engine, allowing a more precise control of the fuel mixture into all cylinders will always deliver the best efficiency over a single carb design with an obsolete 8 valve counter flow head. The 4AFE and 4AGE are the easiest to adapt (though not the most modern). The 4AFE was designed for good economy according to Toyota, but I know of people with Corolla GTS and MR2 with the higher performance 4AGE engine who claim they can get over 40 mpg if they are easy on it. Our car should be similar in that they weigh about the same.

If you are doing an engine swap only for economy that would be a questionable investment, I am doing my own 4AGE swap and my costs will be about $1600 (including a performance clutch) with me doing most of the work, except for the necessary machining and welding. It could be done a bit less, perhaps $1200 if you are resourceful and do a lot of the work yourself, use a stock flywheel and reuse your old clutch, etc. So to go from about 30 mpg to 40 mpg would take about 4 years to break even of normal driving, not counting the 500 hours of work it would take. For about half that cost, and a lot less work you can do quality rebuild and get more modest improvements, and a faster pay back.

The newer engines would be even more efficient, and complex, and likely more work to swap. They are also all aluminum and very lightweight (a lot of plastic parts to save weight). I have examined them, and the bell housing might bolt up, but it was hard to tell if it would be an exact fit. You also have to match the flywheel size and location for the clutch inter face. Go for it and let us know how it all comes together.

[takza]

I'm sort of an mpg fanatic...not that I know all there is to know....

What I think...

* since the T4WD is 4x4...any engine you might put in it from a similar vehicle will result in LESS mpg if it is from a 2WD car....reason? The mass of the rear axles (in the housing)...the rear diff and the driveshaft....ALL needing to be sped up each time you go up thru the gears...not to mention the drag of the gear oil and the friction.

* I think that the easiest and cheapest way to increase mpg would be to do the Suzuki TB mod on the 3AC...used parts and someone has already proven it works...probably better mpg.

* Best mpg would be from a diesel engine...cost and installation would be an issue...great if you can make your own biodiesel.

Easiest way to increase mpg with the OEM wagon is probably synth gear oil/engine oil. Light weight wheels (Miata?) and small tires (all season 185/65/14?). Advanced ignit? Higher than spec tire pressures? A fuel additive? Use a vac gauge and stay off the pedal. Don't put a rack or big lights on top...wind resistance is a major factor for mpg.

I've noticed with my wagon that IF I shift at 2.5K....keep the throttle down just enough to get decent acceleration...I stay out of the secondary and this probably helps mpg by 3 or 4....though I don't always drive this way. Somewhat advanced ignit results in approx 20% more "power"...as tested...but too much advance hurts mpg. RESULT..you go just as fast or faster than OEM...less engine thrashing.

I've seen as high as 38 mpg in summer and maybe 29-30 in winter. 32-34 on long trips in summer with around 600 lbs total weight. My 4x4 Nissan truck with cap will manage 25 mpg on similar trips and same weight.

I've done the kind of camping / adventuring you are talking about for extended periods...if you expect high gas prices in the future...the T4WD is ideal....but space is limited. I did two mods with my wagon for this....removed the rear seat and put in a hinged piece of wafer board...much storage underneath for heavy stuff and you save 50 lbs weight...you can also remove the front pass seat for less weight and more room.

I built a roof rack out of 2x2s...designed for minimum wind resistance. Used to carry lighter weight stuff like tents...tarps...camping chairs..etc. If covered carefully with a tarp (use canvas)...it tends to bubble up when driving...creating an aerodynamic shape that doesn't hurt mg much...if at all. If you use a tent...make sure it is made for mountain climbing...a cheap tent will get torn up in the wind. The trans went out on my wagon from too enthusiastic 4 wheeling...need to recognize the limitations. You don't need big tires offroad...just know how to drive and keep the big rocks from centering where your cast alum trans housing is.

[emmahumpfritter]

I'm also a MPG-head...

Well, I have loads of metro 1.0L parts laying around. Here's proof:

http://minnesota.publicradio.org/displa ... metro_man/

Has someone written up a "how-to" for the TB install?

The stock carbs on these tercels are probably the only bad thing about these cars. To solve that would be wonderful.

Thanks,
Brenton

[ARCHINSTL]

WOW - national NPR !
Way to go, you burly guy...
Tom M.

[sdoan]

Brenton, I don't know about Geo Metros - but that NPR thing is WAY cool!

As for good gas mileage out of the 3A...

I've gotten 40mpg on long summer road trips, but that was somewhat anomalous - 36 mpg seems consistently possible for hwy driving. But if you are not worried about power and acceleration why not try disconnecting the secondary linkage and drive everywhere on the primary. It would really limit the amount of fuel and air the engine would get so it might cut the power too much. But it does seem like a relatively simple experiment.

I think this has been mentioned before, but a small engine working hard can use more fuel than a larger engine loafing. My favorite example is from an original road test of the 260 (4.3L) V-8 Sunbeam Tiger. They were surprised to discover it got better gas mileage than the 1.7L 4cyl. Alpine version OVER 100 MPH!

Good luck,

Shawn

[takza]

I've only just sat in a Metro once...but it was surprisingly roomy. I wouldn't mind one of the hatchbacks...almost like a wagon.

The Suziki TB mod was done by about the original Tercel group member...think he's up in your area. Has some info on a website.

One way to save gas is to install a detent spring on the throttle so that when you press the pedal further than you have it set...you feel resistance. Was looking at how to do this on the T4WD...but it didn't look too easy due to the fact that you probably need to mount the spring on the engine block due to it's movement...need to fabricate something. Had this set up on another car...worked real well...no vac gauge to watch.

[tercelwill]

Someone on the parts section made a 3a a TBI using a cavalier throttle body and a mr2 ecm. sounds cool but it would require a lot of tuning the computer.

As far as the mpg goes I get a cool 35 highway i just drive easy.

The echo motor would fit with tons of modification and v tec on a tercel sounds awesome but i don't think it would be any improvement in the gas mileage. Tercels are heavy and boxy, Echos are light and sleek.