Skip to main content

Written by Don S
----------------

..
... I have been working on this subject many years with the old trucks with carburetors.

The engine converts gasoline to heat as the power source. Fifty percent of the heat is wasted unused and is dissipated though the radiator and exhaust system. Large cubic displacement engines consume more fuel than smaller engines but this is not a ˜hard' fact.

... Here is a list of a few mechanical things that can effect fuel mileage. Cam and ignition timing, cam lift, duration and valve size. Fuel delivery systems, and exhaust scavenging systems. Operating temperatures of fuel and engine. Type of transmission, gear ratios, type of tires, tire size, the tire pressures and the wheel alignment. The vehicle speed, the load, the wind speed and direction. The list can continue on including the gasoline and of course the driver. Here's a thought, is it possible that larger wider tires require less ˜toe in' that could reduce drag?

The driver knowledge and ability is the big factor for achieving the best fuel mileage if the vehicle is in proper condition. Make sure the odometer in the vehicle is showing correct mileage. Keep a record of all fuel amounts, the mileage and the Miles Per Gallon between each gas-up. The record can be helpful in spotting problems with the engine when there is a sudden drop in mileage. Full tank amounts will vary due to air trapped in the tank but the MPG will average out in the long run.

Here are a few thoughts about saving fuel.

First thing a driver will notice when they start to conserve fuel is it will agitate other drivers around his vehicle. Please be considerate of other drivers who have no concept of your economy driving. The other drivers want to race to the next stoplight and remember, if they don't get there quick enough they won't get to stop!

1. Think about driving as an art while doing so. Stop rubber-necking, turn off the music, cell and drive. Errrrr.... Fat chance!!

2. Install a dash-mounted vacuum gauge and use it. As the fuel mileage drops the vacuum needle drops. Try to prevent the needle from dropping below five inches. Readings will change with altitude changes.

3. Drive as if you had a fresh egg taped on the accelerator AND brake pedals.

4. Apply accelerator and brake petals smoothly.

5. Reduce speed as much and as soon as possible. Speeds above 50 MPH eat into the pocketbook!

6. Scan far ahead of your vehicle for traffic control signals and things that will allow you to ˜get off the gas' sooner so you don't have to ˜hit' the brakes as hard – later. The over use of brakes means fuel has been wasted.

7. Drive as if your afraid your brakes are in poor condition and you are trying to save them.

8. Purchase your fuel in the morning when it's cool and keep the tank full.

9. Air you tires up when they are cold and on the plus side of the recommended pressure and check them often especially on cold days.

10. Small amounts of high quality low ash Out Board 2 cycle oil in the fuel (less than ¼ Oz per gallon) will clean and lubricate and reduce friction in the following items for better fuel mileage and life, electric gyrator fuel pumps, carburetor/injector parts, spark plugs, valve stems, compression rings and EGR systems.

11. Air dams can enhance cooling and reduce aerodynamic drag. Bug shields, sun visors, wind deflectors, roof racks and large outside mirrors can reduce fuel mileage.

12. The effect of heavy loads is detrimental to fuel mileage and brake life.

13. Modifying a vehicle with lifts and large wide tires is detrimental to fuel mileage and brake life.

14. Cruise control may save fuel in ˜flatlands' but may not be economical in hilly country.

15. In hilly country do not allow the down hill run to cause engine ˜braking' i.e. slowing down the vehicle unnecessarily. Run your fastest speed at the bottom of a hill and the slowest at the top. If you are on long steep grades it is very difficult to stop while going down hill. On these long grades use engine ˜braking' and even down shift for added speed control and to save the brakes.

16. Allow the engine to warm up and/or drive gently till it does. Cold engines get poor fuel mileage.

17. Put the transmission in neutral or stop the engine when long waits in traffic are encountered i.e. train crossings.

18. Reduce the Air Conditioning and the electrical demands on the alternator. Fancy lights and sound systems burn extra gasoline and bother others eyes and ears.

19. Hey!.. wake-up!! do you have any other ideas?

----------------------
"Give me hope! Ah, sweet madness! Struggle, volcanoes and iron and sadness! A dusty place to kiss the ground, an empty place to cry out loud."
Last edited {1}
Original Post
Path92SE writes:
quote:

I have a somewhat valid question...say you're coming down a hill and you use engine braking. You were at 1500rpm in 3rd, but shifted to 2nd and rpms went up. Since the motor is spinning faster, is it burning more fuel?



Don S replies:

Good question. Hope this will be a good answer.
... Only use engine braking when the vehicle is going to gain excessive and unsafe speed that would have required a fair amount of regular brakes. Excessive downhill braking can cause many heat related problems. Among these are warped rotors, brake fade, boiling brake fluid, wearing out pads, over heating bearings and lubricants.
... Down hill shifting while engine braking is not going to consume very much fuel because the throttle will be closed.

In hilly country it's a case of the having to use more throttle to regain the speed you lost by allowing short periods of unnecessary engine braking.

----------------------
"Give me hope! Ah, sweet madness! Struggle, volcanoes and iron and sadness! A dusty place to kiss the ground, an empty place to cry out loud."
Post

Nissan4wheelers - Home of SWANKy and the AZ Runs. Your #1 source of Nissan Offroad Tech on the web. All site content is copyrighted by the owners of Nissan4wheelers.com. All rights reserved.
×
×
×
×
Link copied to your clipboard.
×