Need help in the Knowledge Department

[rcottle]

I have been searching and reading alot of threads the last couple of days. I have come up with a bunch of questions that I was hoping the brainiacs on here could help me with.

1. Which would get better fuel mileage?
a) 5th gear ratio of .692 & final gear of 3.77
b) 5th gear ratio of .692 & final gear of 3.55

2. Does changing from 12" to 13" tires & wheels increase fuel mileage?

3. Would lowering the car 1" improve fuel mileage?

4. Does anyone make a turbo that can be put on the 1.3L? Would this help fuel economy if driven correctly?

I know thats a lot of questions but I have read alot of posts on here there is a lot of smarts here.....Appreciate any input - Thanks

[elcamino1]

3.55 will yeal better mileage but not much!

[elcamino1]

Switching to 13" will help,but what size 13,s

[FB71]

I have been searching and reading alot of threads the last couple of days. I have come up with a bunch of questions that I was hoping the brainiacs on here could help me with.

1. Which would get better fuel mileage?
a) 5th gear ratio of .692 & final gear of 3.77
b) 5th gear ratio of .692 & final gear of 3.55

2. Does changing from 12" to 13" tires & wheels increase fuel mileage?

3. Would lowering the car 1" improve fuel mileage?

4. Does anyone make a turbo that can be put on the 1.3L? Would this help fuel economy if driven correctly?

I know thats a lot of questions but I have read alot of posts on here there is a lot of smarts here.....Appreciate any input - Thanks

#1 = b
with the same speed gear ratio, a numerically lower final drive will typically yield greater fuel economy.

#2 = no
the diameter of the rim has no direct bearing on fuel economy. The rolling diameter of the tire is what will influence that. However, going to a larger diameter tire, which reduces the RPM of thengine at the same vehicle speed, will also cause an error in the speedometer and odometer. The Speedo will read slower than actual, and the odometer will show fewer miles travelled than actual. This will cause errors in you fuel economy calculations.

#3 = yes
lower the car effectively reduces it's frontal area, which reduces aerodynamic drag, which will increase fuel economy.

#4 = yes and no
there are no turbo kits (that I'm aware of) that are a direct fit for the 1.3L Festy. However, several turbo manufacturers make a turbo that is properly sized for a 1.3L engine.
But, manifolds and fuel/ignition management would be up to you. Lastly, anything that adds power uses more fuel to do so, so I doubt a turbo would increase your economy. But, a turbo would yield more power than the stock engine alone, quite probably with the same fuel economy.

[FB71]

and elcamino is correct. Only slightly better fuel economy.

[rcottle]

So lower the # the better would that be the same for all ratios in aspect to gearing of the transmission?

[packrat427]

[QUOTE=rcottle;187070]I have been searching and reading alot of threads the last couple of days. I have come up with a bunch of questions that I was hoping the brainiacs on here could help me with.

1. Which would get better fuel mileage?
a) 5th gear ratio of .692 & final gear of 3.77..NO
b) 5th gear ratio of .692 & final gear of 3.55..YES

2. Does changing from 12" to 13" tires & wheels increase fuel mileage?... It can little.

3. Would lowering the car 1" improve fuel mileage?... NOT REALLY

4. Does anyone make a turbo that can be put on the 1.3L? Would this help fuel economy if driven correctly?.... NO , but several on here have several on here has installed a turbo on the B3, but once you install one , I don't think you could ever drive it easy ....LOL

[FB71]

only to a point. Too low (numerically) will cause the engine to stuggle excessively, which results in the driver applying more throttle, which increases the engine's load calculations, which increases fuel delivery.

Remember, the transmission gears jobs are to multiply torque to overcome the intertia of the vehicle. Insufficient torque multiplication causes the engine to work harder, using more fuel.

[FB71]

3. Would lowering the car 1" improve fuel mileage?... NOT REALLY

talk with Pu241. He installed FMS springs, and has noted a measurable increase in fuel economy on highway.

[rcottle]

With lowering the car 1" or so and putting taller tires on the vehicle are you still able to make turns as sharp with out rubbing fenders? Is there a 13" (lighter) aluminum wheel & tire combination that will bolt on?

[FB71]

Don't kn ow on the first part. It would most likely be up to you to find out. Second part; I'm sure there is, but it will require you to do some homework involving the weight of different wheels with 4x4.5" bolt pattern.

[rcottle]

Okay - if a turbo were installed to increase power and you could show self control and keep your foot out of it.... One could install lower gear ratios (or would you say higher ratios) for the better fuel mileage?

[FB71]

nope. lower ratio increases the load, even on a turbo engine. That'll increase fuel consumption.

[rcottle]

Thanks for the help everyone - I'm sure I will come up with some more ideas..

[drof 89]

Strip every ounce of unneeded weight off the car. Run the tallest narrow tires you can . Install the best brake system that can be made to work. And coast whenever and wherever you can! A Plymouth Superbird nose,full belly pan,full skirts, a 6in. angle chop with a VW turbo bio diesel also wouldn't hurt. Just kidding.