Any time gas prices climb, we are often asked, “is there anything I can do to improve my gas mileage?”. The fact of the matter, is there are numerous options for improving fuel economy. The racing industry has used all these techniques for generations to go faster, but the part that many people forget is that these same techniques also improve gas mileage.
Wet induction: Wet induction is a system that introduces a small amount of liquid to the air which is drawn into the engine. The liquid is generally water, but can be any number of liquids, such as denatured alcohol, or methanol. The liquid serves several purposes. It cools the incoming air, cools the combustion chamber, increases the compression ratio, cleans the intake valves and combustion chamber, and in the case of denatured alcohol, or methanol, it also increases the octane of the gasoline. All of these factors combine to greatly improve the efficiency of the motor.
Hydrogen induction: Introduce hydrogen into the in coming air stream, much like wet induction.
Propane induction: introduce propane into the air stream, much like wet induction. You can also alter a vehicle to run on propane alone.
Maximize air flow through the motor: Because a motor is just an air pump, any time you make it easier for the motor to move air, you will increase horsepower, but you will also increase fuel economy. Several techniques for increasing the motors efficiency include Port and polish, larger intake and exhaust, ram air systems/ velocity stacks.
Port and polish remains a favorite modification racers use to improve the way their engines produce power. By carefully honing out certain areas of the motor, it allows the motor to more easily draw air into, and push air out of the motor. The less work the engine must do to move air in and out, the more efficient the motor will be, and thus fuel efficiency will be increased. The head, intake manifold, exhaust manifold, and throttle body are all areas that can be ported and polished to improve air flow over the factory design.
A must for improved air flow is upgrading the intake and exhaust. Aftermarket intakes will be larger in diameter, and use a larger, easier breathing air filter. Also, an intake manifold with a larger plenum will allow for a more efficient motor. The larger plenum area reduces the amount the individual cylinders will compete for air, particularly at higher RPM’s. The exhausts will also be larger in diameter and will use larger, faster flowing catalytic converters, while still effectively keeping emissions an acceptable levels.
Another cheap and effective way to maximize air flow is the use of ram air and velocity stacks. Ram air systems use the vehicle’s forward movement to force air into the intake, rather than relying on the vacuum of the motor to draw the air in. Ram air systems also often employ a velocity stack. A velocity stack is simply a specifically shaped cone which increases the speed at which the air enters the motor by gradually tapering the space the air has to enter the motor. It’s based on simple physics; if a gas is moving through a confined space, and the space gets smaller, the air will move faster. The air then travels into the engine faster, and therefore makes the engine more efficient.
Tuning and engine management: One of the most effective ways to improve fuel efficiency is tuning. By advancing the ignition timing, and slightly leaning out the air fuel ratio, the car will greatly improve in power, and fuel economy. There are numerous systems available, ranging from simple off the shelf programming tools which come with pre-made maps, to full blown replacement, stand alone ECUs (engine control unit). All of these different tuning systems can be use to various degrees to improve fuel economy.
Weight reduction: One of the easiest ways to increase fuel economy is to simply make the car weigh less. Steel can often be replaced with aluminum. Many metal items can be replaced with fiberglass or carbon fiber. Body panels can be replaced with fiberglass, or carbon fiber (carbon fiber weighs less than fiberglass and is stronger than steel). Heavy steel rims can be replaced with aftermarket alloy rims (reducing rotational weight, such as the rims, axles, rotors has a dramatic effect on fuel economy). Seats can be replaced with lightweight versions. Heavy gas tanks can be replaced with much lighter fuel cells. Unnecessary items can be removed, or can be trimmed down (brackets, options, features, power windows replaced with hand crank etc) the list goes on and on.
Improved aerodynamics: Improving the aerodynamics of a vehicle will improve fuel efficiency. Body kits, canards, wings and underbelly pans can all be added to improve the ease at which the air moves past the vehicle. The less the car has to fight to get through the air, the more fuel efficient it will be.
Reduced drive train loss: All vehicles have some power lost through their drive train, as it is an inevitable part of the process. We can, however reduce that loss. Water and power steering pumps can be driven my electric motors rather than off the crank pulley of the motor. The motor and transmission mounts can be made much stiffer to reduce the amount of drive train loss due to the engine twisting in its mounts. Drive shafts and axles can be made from light weight materials to reduce the all important rotational weight, and thus also increase fuel economy. The motor itself can also be rebuilt using lighter weight parts (pistons, rods, crankshafts, camshafts, valves) in order to even further push the fuel economy by lowering rotational weight.
Gearing: One simple change is gearing. Just through gearing alone, we can alter a vehicles top speed, acceleration, and fuel economy.
Conversions: The be all, end all, for increased fuel efficiency will always be changing the way the vehicle is powered. Switching to diesel, bio-diesel, hybrid, or even hydro electric motors to power vehicles will be the top end, all out version of the fuel efficient vehicle. Gasoline vehicles can be converted to run on e85 or propane/ natural gas. Any car can be powered by any drive train, it is just a matter of making it happen.
BOB’s and WOW’s: In the automotive industry, there are bob’s (best of the best) and wow’s (worst of the worst). These are parts that meet manufacturer’s requirements, but they are at the extreme ends of the acceptable range. Some cars get all bob’s, some get all wow’s, most get a combination of the two. We will simply use nothing but BOB’s, as we will be able to strictly control the quality of product we are using.
Address pattern failure: Yet another ugly truth the automotive producers would rather not discuss is pattern failure. All vehicles have inherent problems with them. These inherent problems are referred to as pattern failure. We address these problems by using higher quality parts and engineering. By eliminating pattern failure, we will produce a better vehicle.