gas mileage

takza · Post by **takza** » Thu Aug 05, 2004 4:57 am

If you have the auto, I'd say you are doing real well.

I have an old Consumer Guide from '86 that gives a figure of 25.6 MPG overall (city/highway mix for the 4WD with auto.

Put some 175/80/13s at 32 PSI on there to reduce your RPMS and I'll bet you'll see 33 on the highway.

Here's a page I've recently found with some interesting MPG info:

<a href='http://www.lubedev.com/articles/' target='_blank'>http://www.lubedev.com/articles/</a>

<a href='http://www.lubedev.com/articles/tips.htm' target='_blank'>http://www.lubedev.com/articles/tips.htm</a>

<a href='http://www.lubedev.com/articles/mileage.htm' target='_blank'>http://www.lubedev.com/articles/mileage.htm</a>

Got my can of actetone out now.........

sacwac · Post by **sacwac** » Thu Aug 05, 2004 10:02 am

takza,

great stuff there, I've read most of those articles...

I might try the acetone solution myself, but I should concentrate on getting good mileage by fixing my current problems first.

I'm very interested in the results.

tercel4wdrules · Post by **tercel4wdrules** » Thu Aug 05, 2004 10:09 am

I was reading the fuel economy for the '86 4WD auto at http://www.fueleconomy.gov and they say that it has 24 MPG on the city and 25 MPG on the highway. It also says that the '86 manual 4WD gets 27 in the city and 32 on the highway. Although many people have been getting 30 MPG in the city.

takza · Post by **takza** » Thu Aug 05, 2004 5:27 pm

I'm trying the acetone in my other car right now...but it needs an O2 sensor...which I ordered today.

Got around to reading most of those articles yesterday and am going to change some things according to his ideas...like using 1/2 15W40 diesel dino oil and 1/2 10W30 synth oil...both Mobil. Already use a Pure One filter.

Also putting about 1/2 85W140 / 1/2 Mobil 85W90 Synth gear oil in the trans-diff...makes sense for a trans with 220 K miles?

Will also go with the NGK plugs at next change.

Can't find Chevron-Texaco gas around here though.

<span style='color:blue'>WHO is getting 30 MPG in the city?</span>

don1 · Post by **don1** » Sat Aug 28, 2004 3:53 pm

try adjusting your valves

dug320 · Post by **dug320** » Sat Aug 28, 2004 7:11 pm

My stats

Over 5 - 3000 mile, mostly highway, trips I averaged 31 mpg. No A/C 5 speed 1985 SR5 wagon fully loaded.

I WOULD LOVE TO PUT IN FACTORY CRUISE CONTROL but can not find one. This would save my right knee.

While driving around town I measure by distance/tank. I average 205.2 miles per tank.

One decarbon trick that I learned while working at a Chrysler dealership, :blink: . Prior to a tune-up we would pour a can of CCC Combustion Chamber Cleaner. CCC is available at any autoparts place. Makes one heck of a smoke! Worked well without damaging the head gasket.

I have always questioned mixing the oil grades but I bow to those with greater experience.

I have used 5W 50 syn. Works really well without going to syrup in cooler weather. As I am in the process of changing engines, I plan to use 10W 30 syn.

The 85W/90 Syn works well in older transmissions. I found my shifts to be a little smoother.

3A-C Power · Post by **3A-C Power** » Sun Aug 29, 2004 12:23 pm

I managed to find a factory cruise control switch at a junkyard through car-part.com. If you search for cruise control actuator or something like that, for the 83-88 Tercel, it comes up with several results.

GTSSportCoupe · Post by **GTSSportCoupe** » Thu Mar 31, 2005 12:13 pm

OK, I just need to rant a bit about my fuel economy:

I'm getting around 20-22mpg in the city and around 22-24mpg on the highway.

The way I look at it, having a gutless car is ok, as long as you are getting pay back in fuel economy...but I'm not!

I've done everything I can think of to the car. It's got a perfect condition low km engine which has high quality new everything (thermostat, cap/rotor, plugs, wires, air filter, mobil1 syth oil, 92 octane gas, timing belt, full new exhaust, etc etc).

The car has excellent power (best of any 3AC tercel I've been in). Choke, idle, etc works awesome.

I just don't have time to play around with things to try to get better economy these days. The bad mileage is almost enough to make me want to sell the thing. My Cressida has 100hp more and gets the same mileage. My old 87 tercel did get much better economy.

I have not tried messing with some of the more advanced things such as a carb rebuild, cleaning EGR, etc. I guess I should try, just no time...

takza · Post by **takza** » Fri Apr 01, 2005 3:52 am

Well....you have mentioned driving pretty hard....cruising at 3.5-4K?

Best bet is probably to go thru the emissions gizmos and test them.

* working EVAP system helps MPG

* mixture control...O2....the #$^%%$^ thinga-ma-bob on the pass fender...etc?

* I think your tires are undersized?

* use 87 octane and save some $...it burns better

* acetone.........http://pesn.com/2005/03/17/6900069_Acetone/

"Incidentally, in almost all cases, the lowest octane is best for mileage. Most modern vehicles do not have high enough compression to justify using high octane fuels. The testing indicates best mileage is usually obtained with 85 or 87 octane gasoline. Too much octane causes a loss of power and economy. BUT too little octane causes the same things plus knocking."

Don't shoot the messenger....... B)

GTSSportCoupe · Post by **GTSSportCoupe** » Fri Apr 01, 2005 9:51 am

takza wrote: Well....you have mentioned driving pretty hard....cruising at 3.5-4K?

Best bet is probably to go thru the emissions gizmos and test them.

* working EVAP system helps MPG

* mixture control...O2....the #$^%%$^ thinga-ma-bob on the pass fender...etc?

* I think your tires are undersized?

* use 87 octane and save some $...it burns better

* acetone.........http://pesn.com/2005/03/17/6900069_Acetone/

"Incidentally, in almost all cases, the lowest octane is best for mileage. Most modern vehicles do not have high enough compression to justify using high octane fuels. The testing indicates best mileage is usually obtained with 85 or 87 octane gasoline. Too much octane causes a loss of power and economy. BUT too little octane causes the same things plus knocking."

Don't shoot the messenger....... B)

Hey takza, I think you are dead on. I guess I just have to dedicate a day to working on the things you mentioned. The reason I'm burning 92 octane is twofold: I have my timing advanced 5 degrees from stock - this makes a big power difference, but my engine knocks unless I use at least 92 octane. The second reason is the higher octane fuels in Canada have cleaning additives. If I run a cheaper gas here and look at my plugs, they are more black and sooty. When I use the more expensive 92 octane gas with additives, my plugs are a nice light brown tan color. I don't want carbon buildup in my engine and want it to run nice and clean.

Maybe reducing my ignition timing and running 87 octane would increase my fuel enconomy?

As far as driving style goes: In the city the car does lots of stop and go and sitting in traffic. On the highway the car is always above 70mph. I gear right down on hills to keep the car's speed up (and yes, we do have a lot of hills where I live

. So I guess none of these things help. But still it is such a tiny little engine, I would have expected better.

Thanks,

Nick

Typrus · Post by **Typrus** » Fri Apr 01, 2005 12:55 pm

I don't remember where unfortunatly, but I found an electronic ignition system for the Tercels. If you throw some high conductivity wires on there with some iridiums, you should see a good improvement.
Run some Sea-Foam thru the system for a tank and buy a can of Deep Creep (can spray Sea-Foam) and blast the crap out of your carb. Keep it alive with the little throttle linkage on the back. You DEFINITLY do not need the entire can for this. Deep Creep is also a good lube and penetrant. Just initially spray it in with the engine running for about 2 minutes, bursts in either barrel, then at the end of the 2 minutes, kill the engine with a mass burst in as much of both barrels. Allow to sit for a good period of time. 2 hours is a very good time, but 30 minutes will do. Then start it back up. You should get some toxic sulfuric fumes coming out of the exhaust. Let it run for maybe 45 seconds then give it some more spray, light bursts in either barrel, keeping it alive with the throttle. Do this for another 2 minutes. Remember, the Sea-Foam traditional can should have already been poured into the gas tank. After that, shut the engine off and let sit for about 15 minutes. Then give it a good strong 4 mile drive with good hard starts, to blow all the stuff out. Then, spray about a 5 second burst in each barrel before continuing your daily routine. This works best if you wonÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢t be driving for a while. With mine, I let it sit over night. This helped decarbon my engine in a massive way. And man were those fumes horridÃƒÂ¢Ã¢â€šÂ¬Ã‚Â¦ I can still taste the sheer yuckÃƒÂ¢Ã¢â€šÂ¬Ã‚Â¦ But still, better its removed and your economy goes up.

3A-C Power · Post by **3A-C Power** » Tue Apr 05, 2005 5:29 pm

My car gets bad mileage because the alignment is so far off that 20% of the engine torque is used to push the front wheels into eachother. It torque-steers to the left under acceleration and right under braking. I'm predicting a huge increase in mileage after the front end is fixed.

takza · Post by **takza** » Wed Apr 06, 2005 3:58 am

I'm only averaging 27-28 MPG in the winter....I also have the lower final ratio ('83-'84). Tires are about stock diameter. Heated fuel and covered radiator didn't help any in winter.

Typrus · Post by **Typrus** » Wed Apr 06, 2005 3:00 pm

....... Oh crapenstein... Those lower ratios ARE NOT going to help with my driving condition unless it snows or I have a big load in the back. I have an 11+ mile trek to school (I found a short way.. Just don't tell the neighborhood lol) And 7 miles of it it wide-open cruise. Bah.. Guess I'll need some good ole-fashioned big tires when I get the money. Even 750 revs per mile is a massive improvement from 850 or whatever 175/70R13's are. Maybe if I can find some oldish Passat rims.. They are 4x100's and are 14x6. I could pop in some nice Toyo Tires... (speaking of that, they say their Premium 800 line of 175/70R13's turn at 913 revs per mile... Ouch)
Actually, I'll just give their info things. (Their site is more in-depth... I just had to line stuff up)

Tire Size-------------Rim Width In.-----Max Load (lbs.)---Revs Per Mile

P205/75R14 95T*----5.0-6.5-7.5---------1532-----------------792

P215/70R14 96T*----5.5-6.5-7.5---------1554-----------------798

P185/60R14 82T------5.0-5.5-7.0 --------1047-----------------908

P175/70R13 82T------4.5-5.0-6.0--------1036-----------------913

P185/80R13 90T*-----4.5-5.0-6.5--------1301-----------------842

(Shrug)

takza · Post by **takza** » Thu Apr 07, 2005 6:28 am

Various tire sizes and speedometer errors for 13" & 14" tires:

* 175/80/13 are 3% greater diameter than OEM

* 195/60/14 are 1% less diameter than OEM

* 205/60/14 are 1% greater diameter than OEM

* 185/70/14 are 3% greater diameter than OEM

* 195/70/14 are 5% greater diameter than OEM

* 205/70/14 are 8% greater diameter than OEM

* 185/75/14 are 6% greater diameter than OEM

* 195/75/14 are 8% greater diameter than OEM

* 205/75/14 are 10% geater diameter than OEM ... Dust Magnet/Downey

I have 196/60/14s now...will go to 195/70/14s?

I got 5 MPG more with 175/8013s that were inflated to 32 PSI...rode pretty hard though. Real crap on corners.