85 Tercel 4WD Wagon - Where to start?
 

Aeropimp my ride!

Heh heh, at least it doesn't have the stock roof rack. :rolleyes:

Honestly I think aero is the least of my concern since most of my miles are at 40 mph or less. Rolling resistance seems to be a bit high. Regardless, what would you do?

I've already blocked off the upper grille, but this was more to get the heat up faster on cooler days and doesn't really seem to do squat for FE. I've thought about wheel skirts and discs, but let's be realistic here - it's a moving trapezoid!

Almost forgot to mention that when this body shape debuted, Road & Track made a remark about it having a new aerodynamic shape. It makes me chuckle to think about it.

My goodness! You've got quite a pickle there. I would imagine underbody paneling would give you the biggest first improvement. I would imagine the stock 4 wheel drive system is an aerodynamic bugger.

If it is at all possible, you should make it either front wheel drive, or rear wheel. Having all 4 wheels being driven really takes a toll.

Without changing the transmission, I suspect the 4 wheel drive final gearing is probably fairly high, which will cause the engine rpm to be higher, which in turn will use more fuel.

I'm not up on the mileage, but your shape is pretty similar to my 89 Honda Wagon. I am able to get high 30's out of mine, while still driving on the fast side.

One other thing you can do that may help, some, is increase the pressure on your tires, to at least as high as the max pressure, on the sidewall. I had mine up at 55 and it makes a marked difference in rolling resistance. It does affect treadwear a little, but not nearly as much as I would have expected.

Oh, welcome to GasSavers, too.

Some humor Gary? Snax has been around for a bit.

You guys are making me severely jealous with your wagons! I want an RT4 Wagovan so bad I can hardly stand it! :D

Naw, some spacing, on my part, that's part of Whoop's, in my cars name?

What're yer trans/axle ratios? I'm betting gearing could be behind the mileage issues. 4WD doesn't seem to impact efficiency nearly as much as throttling losses do IMLE.

I'm getting 32-33 mpg mixed in summer with the same car. 30 mixed last winter.

Compared to the Ford Escape Hybrid at 27 mixed (EPA). It's maybe 1/2 ton heavier and more power.

Toyota did the smart thing on gearing by installing an 'extra low' gear vs. gearing down the final drive, so it really isn't that bad with a 3.73 final and .83 OD. I doubt taller tires would do much for me around town.

Frankly, as far as aero goes, I'm thinking of just going totally the wrong way with it by fabricating two A-10 Warthog style engine nacelles to mount on the roof. ;)

I think a large part of the rolling resistance problem is really the tires. The 155 width cheap snow tires on it right now seem to deform a fair bit radially even at 45 psi - which is their maximum rating. Likely the only way to see real improvement through the driveline however would be to remove the rear differential, but that's not really an option since I actually need the 4WD.

Regardless, I'm hoping to see considerable improvement in my FE soon, as I have a new carburetor to install. Right now the car just stinks of raw fuel if I get on it very hard.

Oh, and I also just realized that I do in fact have an 83. :P

I think they will. For my Rabbit w/ pretty much the same sized engine (1.6l) and a slightly taller OD gear ratio (3.89/.71), and it would still benefit from larger diameter tires when cruising at or under ~40mph. The alternative being to P&G, so it yer already doing that and seeing lousy numbers then ya may want to see what's up once ya get the carb on and everything running right.

Try replacing all the driveline lube with synthetic.
Transaxle and also the "rear end" or whatever it's called on that car.

I keep reading that the mechanical losses in 4wd systems are worse than in 2wd. So help yourself by giving it the best lube you can get. Might still have the original stuff in there now!

The problem I see with these 4x4 wagons is that as soon as someone buys one they want to jack it up and make it look tough. Which means the car usually just gets trashed. I've put 50K on mine...and have had it off road camping enough to seriously test out the 4WD and trash the trans. Also squashed the exhaust tip and dented the floorpan and so forth.

I found more or less by being CHEAP that going with 14" steel wheels and sticky all season 60 series tires and boosting the coils that you can have a very good handling car on road and off...and in the snow.

All you need to do with the OEM carb rather than the Weber...is to remove all the vac crap and just go with ignit advance...canister...maybe EGR. One guy got very good mpg doing this.

These aren't impressive cars until you hit some snow or mud...need to carry something large...or fill it up at the gas pump. Then you start to realize what you have.

Ahhh, Tercel 4WD. I love those cars. Very rare to see them anymore....

It looks like the 155 width tires are actually 20mm narrower than stock. That makes them a nice choice for plowing through slush, but I really think they are a large part of the problem. I may just swap on my MR2 wheels and tires in the spring if they will fit (since it just sits sans-motor for lack of EV conversion funds). It currently has high performance 195/60-14s on it which should answer that question pretty well.

I'll definately be switching out my lubes to synthetic as I proceed along with taking care of all of the things the PO did not - though one of the reasons I bought this car two months ago was because they already had replaced a whole mess of stuff.

As for the carb, I just installed the Weber yesterday. I think I spent half the time just trying to figure out what half of that mess of vacuum lines was for. I still don't know what the majority of it was. It's just down to the EGR and ignition advance now, so now I can actually see where stuff goes. It seems to start much more cleanly now when cold without having to jab at the pedal to keep it going. A choke that works! ;)

I've got 195/60, but they are all season. Do real well offroad and in the snow. People using synthetic oil don't seem to get such good results...I use regular gear oil and some moly additive. You'll need to jet that carb down for mpg?

Actually I don't think jetting is off at all on the new carb. Cruising at 1500 rpm, I can get it to start misfiring just by leaning out the idle mixture. It'll dump a fair bit of fuel in when I step on it, but it seems to run toward the lean side at lower throttle, so I'm expecting to see some improvement.

Will be interesting to see how you do with it.