Project MPG

[HighMPG]

This is my first time ever trying to save gas in my whole 17+ years of driving.
I have been known to have a heavy foot and love racing mazda rotary cars, which suck gas like a V-8 but it's a small 1.3 liter. Since I do not have any running rotary vehicles right now I will start my daily beater, driving slower, keeping my RPM below 2500rpm and feathering the throttle. I know with an attitude adjustment of my right foot and if I can just fight my addiction for acceleration and speed I should get decent mileage.
What we have here is a 1990 Toyota Corolla SR5 Coupe 4 speed Auto.
154k miles and I just filled a full tank up today with the idea of seeing how many maximum miles I can get out of one tank.
This car is original and un-modified. Dead struts which I will replace after I get a decent read on the car's current fuel efficiency just the way it is and on a full tank with my regular driving habits.
The fuel tank is about 13.2 gallons max or 50 liters.
If I am driving properly and squeeze about 25-30mpg i should see about 300+ on a full tank.
I know the car needs spark plugs/wires, I recently gave her some Castrol GTX but will switch over to synthetic across the whole car once I finish High MPG testing and Normal MPG testing.
I do not go on very many long trips, averaging about 10-15 miles max a day but 20 dollars would last me 1-2 weeks sometimes but this is actually the first time I am paying attention to my MPG.

Here is a list of what I have planned.

New iridium plugs and nice performance wires with an addition of MSD or some type of spark enhancing device.

Good set of tires

Lowering vehicle with some springs and tokiko struts

Under body paneling

Removing Wipers for non rainy days

Removing mirrors and moving inside the car

Weight reduction

Front lip

And more as we go.

Here is a photo of the mileage when I got my full tank of gas at $4.219 a gallon. I only needed 8 or so.

Still costs 4 times more then when I started driving so I guess it is time to pay attention to my footprint!

[HighMPG]

VEHICLE DIMENSIONS
Specification 2-door coupe
Wheelbase, in. 95.7
Overall Length, in.172.2
Overall Width, in. 65.6
Overall Height, in. 49.6
Curb Weight, lbs. 2414
Fuel Capacity, gals. 13.2

Frontal Area: 18.53 sq ft

This cool calculator helped me figure out all my ratings and drag
Vehicle aerodynamics

[Frank Lee]

That is a fun calculator but it helped me to already know what the Cd of the car I inputted was.

[oil pan 4]

Originally Posted by HighMPG

I do not have any running rotary vehicles right now

I use to have that problem too.

You could also try running taller tires. I think pretty much every one who has tried it saw good results.

[jakobnev]

Just a couple things i thought of while reading your post:

1. Feathering the throttle is a typical rookie mistake, it's the brake pedal you need to learn to avoid. (There are threads about how to accelerate).

2. Unless you have a misfire, boosting the ignition system isn't going to give meaningful improvement. (That includes exotic plugs)

3. Increased tire pressure should be on your list, it's cheap, easy, and effective.

And welcome.

[HighMPG]

Originally Posted by jakobnev

Just a couple things i thought of while reading your post:

1. Feathering the throttle is a typical rookie mistake, it's the brake pedal you need to learn to avoid. (There are threads about how to accelerate).

2. Unless you have a misfire, boosting the ignition system isn't going to give meaningful improvement. (That includes exotic plugs)

3. Increased tire pressure should be on your list, it's cheap, easy, and effective.

And welcome.

Thanks for the pointers, I was already reading hypermillers coast and circle or find a spot you can coast into. I used to own a bmw with one of those MPG readers so I had an idea, feathering the throttle is not a rookie mistake but part of saving gas. I can just use a light throttle all day and brake as I wish and will still be saving gas compared to my normal driving which includes putting the pedal to the metal! lol

I believe any improvement is a good improvement, . Bigger bang at any current throttle position will give much better combustion and cleaner possibly?
I am not doing anything right now except giving it light throttle and yes, it causes me to use the brakes less and catch the lights here in Oakland, CA.
I am taking the same trips, 70% city 30% highway and just using less throttle and brakes. Maybe I didn't mention that but you should know that goes hand in hand typically.

And the tire pressure Idea I will put into effect once I burn this tank of gas off. thanks for the pointers tho. I actually need to buy a whole new set for the rainy season, if it ever comes.

[euromodder]

Originally Posted by HighMPG

feathering the throttle is not a rookie mistake but part of saving gas.

When you need power - as when accelerating - it's good to make that power as efficiently as the engine will let you.
Strangely enough, you don't get that by feathering the throttle, but by accelerating at the best Brake Specific Fuel Consumption - BSFC - where most horses are fed using the least fuel.
This usually means giving it a good go, say 80% load, at low rpm.
It's how pulse and glide becomes more efficient than steady state driving.

If you can find a BSFC chart for the engine, you can see where it makes its power most efficiently.

For (more or less) steady state driving, feathering the throttle is OK.

[HighMPG]

I just donated and got my MPGuino on the way!

[HighMPG]

Originally Posted by euromodder

When you need power - as when accelerating - it's good to make that power as efficiently as the engine will let you.
Strangely enough, you don't get that by feathering the throttle, but by accelerating at the best Brake Specific Fuel Consumption - BSFC - where most horses are fed using the least fuel.
This usually means giving it a good go, say 80% load, at low rpm.
It's how pulse and glide becomes more efficient than steady state driving.

If you can find a BSFC chart for the engine, you can see where it makes its power most efficiently.

For (more or less) steady state driving, feathering the throttle is OK.

Thanks man! I actually learned something new! and I am not being sarcastic!
I guess getting the MPGuino will help me better understand and observe.
So it's ok if I use up to 80% throttle before my set 2500rpm limit, get to my coasting speed sooner and coasting longer = more MPG if I am understanding you properly? Thanks

[jakobnev]

Originally Posted by HighMPG

feathering the throttle is not a rookie mistake but part of saving gas. I can just use a light throttle all day and brake as I wish and will still be saving gas compared to my normal driving which includes putting the pedal to the metal! lol

This may come as a shock to you, but the throttle actually has positions in between! And one of those positions is the optimum.

am not doing anything right now except giving it light throttle and yes, it causes me to use the brakes less and catch the lights here in Oakland, CA.
I am taking the same trips, 70% city 30% highway and just using less throttle and brakes. Maybe I didn't mention that but you should know that goes hand in hand typically.

What causes you to have to use the brakes, is not pushing the throttle too far down, but not having the sense to let off in time.