Can you take a pic of the light? Maybe we can help. There is no shift light on these cars BTW.

 

1. Meager if immeasurable gains. PS is freewheeling with no load until you turn the wheel. Highest loads are when you're parking and not covering very many miles anyway.

Best MPG gains are in aero mods. Most ignored area is under-body panels and rear diffusers.

 

Does the 95 Corolla have OBD-II? If so, get yourself some type of instant feedback instrumentation. (Ultragauge, Scangauge, Torque . . . . ) The biggest gains will be seen with driver modification which instant feedback will give you.

You've already got the best transmission for your goal, you just need to learn how to best manipulate it.

Removing the PS belt will provide minimal gain & not worth it to me anyway.

 

You'll put callouses on your hands, as well as wear out the steering wheel cover, not to mention stressing the steering shaft and bearings in your steering column.

 

I've driven my car with the engine off. The steering requires only slightly more force at parking lot speeds and practically no additional force at normal speeds. PS likely costs 1-2 MPG.

 

Interesting. I thought the pump was more parasitic than that, being that this engine is SO tiny. I can turn my wheel with one finger while at speed, and in parking lots it turns like butter. This is what led me to believe losing the PS belt might be worth some mileage gains, but if it's that negligible then I'll wait for the pump to die first.

As for the light, it is located in the center/bottom of the speedometer next to the "mph/km/h" writing. I'll upload a pic.

Third question: Would making a "DIY underbody panel" be a noticeable increase in mpg? I've found success stories for other cars which leads me to think it would be worth the effort. I do have a boost gauge from an old car I plan to install as well for feedback.

 

That's your airbag light

 

Huh, I don't think I've ever seen a light there. I can check for you in my spare cluster, I'll report back in a few hours.

As for underbody panel, I don't think anyone has done it but I've heard great things about it.

 

Here's a better angle. You can see the square looks just like the other areas where the other warning lights light up. I had my key turned to "ON" with the engine off when I took this pic.
My first thought was that it was a shift light with a burned out bulb. Then I thought maybe it's a redline light, but that seems unnecessary/unlikely.
Not curious enough to pull the cluster =P

 

You are correct that there is a light there - page 4 here: http://www.toyota.com/t3Portal/document/om/OM12671U/pdf/1-1.pdf

I can't recall which it is though. Look at page 6 and compare to the ones that light up when you flip the ignition on, and what's missing is likely your light in question.

 

Just had a thought, what about a different tire size to lower the final drive ratio?
I understand a larger/heavier tire will be harder to turn initially, but for someone like myself who cruises mostly highway (100km/h+), wouldn't the increased diameter of the tire give me more distance covered per revolution, thus better mileage? Or am I overlooking something fundamental here?

I've already looked over on ecomodder, but couldn't get a satisfactory answer. I'm talking like a maximum 3-5% increase in sidewall, 20mm or so. No increase in width.

 

Thank you 94rolladad! The light in question is a "Service Reminder light".

 

The bigger the diameter and circumference, the more distance covered in a rotation, yes. But you would need more energy to do a full rotation than with a smaller wheel. I don't think you would gain anything in regards to mileage.

 

Hmm really? What do you think of this observation I noticed on my other car. Seems counter intuitive.

My other car had tire size 205/55r16 tires on wheels that weighed 16.6 lbs each. I switch to tire size 205/50r16 on wheels that weighed 13.4 lbs each. I thought I would gain mileage by reducing rotating mass, but I actually lost 80km to a tank.

This anecdote is what leads me to believe that a larger tire diameter will yield a better mpg rating when the car is driven 90% highway speeds due to the larger distance per tire revolution.

I understand when you say it will take more energy to turn the tire because it is larger/slightly heavier, but my question is, won't the extra weight/resistance of the larger tire be negated by the vehicles momentum? This is what I observed on my other car.

However, my other car has more HP and more TQ, and more TQ at a lower rpm relative to the corolla, so what might work for one car may not work for another based on those extra variables. This would support your point.

 

Changing the tire diameter will affect the speedometer and I believe the odometer as well. If you were to use the vehicle's odometer/trip meter after changing tire diameter it might mess up your mileage calculations. There's a lot that goes into mileage though, for instance I think how the 'weight' of the wheel is distributed can have a large impact, as can the rolling resistance of the tire itself (which is why cars like Prius's have hard economy tires).

 

the diameter is really the only thing that matters for the speedo/odom... a lighter rim and tire assym. will have less rotational mass and increase mileage by a tiny amount (it does wonders for throttle response and traction though)

 

It's an airbag light on my 96 cluster.

 

damn bro... beat me to it by 4 minutes... but i just remembered cause mine was always on.... I was too lazy to reset it every week. i dont even remember how to do it anymore...

 

okay, first off, im pretty sure the dash light in question is actually the airbag light... and if it NEVER turns on, that means somebody likely didnt know how to reset it and removed the bulb or it burnt out.... this ALSO means that your airbags will not deploy in the event of an accident... you should really look into that...

as for the MPG, with a 205/55/16 tire vs say our 185/65/14, there is a 1.5" height difference. this creates less revolutions per a given distance and in the end will actually make you lose MPG (based on what the car calculates for miles). Your car will register speed and miles based on the factory tire size, a half inch difference in height usually equates to seeing 65 on your dash but really going something like 68.9? (math... ugh) Consider this with miles, in this scenario your speedo is under by about 4mph, your actually not registering 4 miles for every 65 you travel. This will make it appear as though you have lost gas milage.
there have been many discussions here about tire sizing and such in these forums.

 

Weazler - I was comparing the 205/55r16s to my 205/50r16s, not my corolla wheels. I see what you're saying though, just wanted to clarify.

As for the light being an airbag light, I didn't even think this car had airbags. I don't really care if it does, the steering wheel just looked too small for an airbag compared to my 1998 steering wheel.

Yours is an airbag light, but yours is a 1996. Mine is 1995, don't know all the differences if any. What does your steering wheel look like?

 

mine is 94 and its also the same for tach and non tach clusters... you should really look into this light, faulty airbags can cause a really bad day.

 

If your steering wheel is stock then it's the same as everybody that has a 7th gen Corolla. The driver airbag was standard on the 7th gen.

 

1996 Saab with a tire going flat

I drove 1,700 miles on a tire that slowly lost air. I did all the calculations for the changes it had on actual miles driven versus mpg changed. The MPG falsely went up and down with the circumference changing. The mileage never changed.

In a way, this is a much better experiment because I guarantee you the weight of the tires never changed.

Normally, they talk about under inflation hurting your mileage. More friction in the tire turned into heat, is energy lost for going forward, but this was super cold winter, so I think the that a control was in place keeping the rubber harder like it was colder despite changes in PSI and heat going into friction.

The last one was my best guess, I didn't own a laser guided thermometer to know the tire temperature! lol (I do now, but who'd purposely have that situation??)

 

accuracy limites

I drove 1,700 miles on a tire that slowly lost air. I did all the calculations for the changes it had on actual miles driven versus mpg changed. The MPG falsely went up and down with the circumference changing. The mileage never changed.

In a way, this is a much better experiment because I guarantee you the weight of the tires never changed.

Normally, they talk about under inflation hurting your mileage. More friction in the tire turned into heat, is energy lost for going forward, but this was super cold winter, so I think the that a control was in place keeping the rubber harder like it was colder despite changes in PSI and heat going into friction.

The last one was my best guess, I didn't own a laser guided thermometer to know the tire temperature! lol (I do now, but who'd purposely have that situation??)

Note: the mileage being the same with the distance travel calculated in was the "same" with a +/- 3% accuracy of no change.

 

There's a tonne of threads on here about improving mileage. Here's a recent one: http://www.toyotanation.com/forum/130-7th-generation-1993-1997/1065306-test-pipe.html

Some sites with really good info:
http://www.ecomodder.com
http://www.cleanmpg.com
http://www.mpgresearch.com

Actual cars that have been modded from mid-30s MPG into 90 MPG+:
http://www.tercelreference.com/project_development/60_mpg_paseo/60_mpg_paseo.html 60 mpg
http://www.aerocivic.com 95 mpg!!!

Note that taller tyres and/or taller gear ratios don't actually require more power to turn. For the same road-speed, the taller tyres/gears require more TORQUE to turn, but at a lower RPM. Since POWER=(TORQUE*RPM)/5250, higher torque & lower RPMs yields same power. So the car would still require 12-bhp to go down the road @ 65mph. However, lower engine RPMs with larger throttle opening puts the engine into a more efficient operating-zone with lower pumping losses (less manifold vacuum to fight the pistons).

But the difference in taller tyres aren't that much 2-3% in rolling distance. Gearing is more effective with the 4-spd auto in the 7a-fe having top-gear that's about 20% taller than the 5-spd manuals. At 70mph, the engine's turning over at a calm 2500rpms. This lets those cars reach 38-40mpg even with larger engine (with lock-up clutch, it's same as manual for power-transmission efficiency).

 

Could car have been in minor wreck that set off airbag? And they didn't replace wheel and just took the bulb out? Lots of shady shops out there.

 

Driver's side airbags were standard on 1993 models, I think passenger side airbags were standard in 1994 but not sure about that one. Either way, all American and Canadian 7th gens had airbags. Unless a previous owner swapped in a non-airbag wheel... pics?

 

A bigger difference than tyre height is tyre width and pressure. Going to a narrower tyre blocks less air. Along with wheel-covers that give a smooth outer surface really aids aerodynamics. Running 175/55-16 tyres at 55-60psi with flush wheel-covers is probably worth 2-3mpg. Think about what those triathletes/bike time-trialists do with their wheels & tyres.

 

A bigger difference than tyre height is tyre width and pressure. Going to a narrower tyre blocks less air. Along with wheel-covers that give a smooth outer surface really aids aerodynamics. Running 175/60-16 tyres at 55-60psi with flush wheel-covers is probably worth 2-3mpg. Think about what those triathletes/bike time-trialists do with their wheels & tyres.

But a 175/60/16 is almost an inch taller than factory for us....no good.

 

Correct, 1994 has dual airbags. First year of that configuration.

 

So changing tires is futile. PS stays.

As for the airbag situation, it doesn't say "SRS AIRBAG" anywhere in the car. I've been in a few wrecks, airbags never made a difference. They're for people who don't wear their seat belts if you ask me, so I'm not worried if there is none. My subaru doesn't have any and it's triple the hp

 

Bold (and uneducated) statements. Ah well, that's the Internet for ya!

 

Walmart customers??>