Believe it or not, people have been building their own hybrid electric vehicles for years. Before the gas-electric hybrid hit the market, the only way to own one was to do it yourself. These hybrids were mainly a result of the low range of electric vehicles (EVs). As EV owners and prospective EV owners looked for ways to increase the range of their cars, many found adding a small combustion engine to their electric motor setup or augmenting their original combustion engine with an electric motor an acceptable compromise. Though this route eliminates the possibility for oil independence, it also allows Earth-conscience drivers to be able to greatly surpass the distance allowed by poor battery capacities of previous years. This movement to hybridize the EV took two directions: one method adds an electric motor to assist the internal combustion engine (as you would find in today’s commercial hybrids), and the other adds a combustion engine to an EV vehicle to act as a generator that could constantly recharge the car’s batteries.

Why Go DIY?

But why would anyone build their own hybrid in this day and age of commercially available hybrid vehicles? There are a few reasons to do this: many people enjoy building things, especially cars, in a totally unique way; the second reason being that you can build a hybrid out of almost any car (even your favorite 70s VW van); and finally, by building your own hybrid amazing gas mileage is much more possible, and you can drive on electric only operation for most short trips. The argument for building your own hybrid is a rather simple one in the end; if you want better gas mileage, a more environmentally friendly vehicle, and a totally unique look, you should go for it. While the hands on, do it yourself, approach is generally reserved for those who have worked on cars for ages, there are still opportunities for people who are relatively new to the car scene to learn the techniques and gain the necessary skills.

Before the options, process, and materials are explained, there are just a few things that should be cleared up. Going from gasoline to gas-electric is a big job, and will require a lot of research and planning. Automotive skills are necessary to completing this job, and even those who have been working on cars all their lives will spend days completing a project of this scale. Most of the work that will be done on a hybrid conversion will be custom, unless you choose a car like the Volkswagen Rabbit or Porsche 914 that has been widely used for EV conversions in the past. That being said, lacking automotive skills will not doom, if you can call it that, you to driving a Prius or Honda Insight. It is still possible to recruit an aide who loves cars and gas mileage, or find an inventive shop that can put together a hybrid conversion. In fact, there are some shops and people that specialize in these types of conversions.

The "Classic" Hybrid

The first option is the one that most commonly comes to mind when you talk about hybrid vehicles: a car primarily powered by and internal combustion engine, but has a smaller electric motor that runs off of batteries that assists the gasoline engine. Though this is how commercial hybrids like the Insight, Civic Hybrid, and Prius are run, it is also the most complicated when you do it yourself. Because both the gasoline engine and electric motor are providing force to move the vehicle at the same time, the main issue is how to allow both motors do work in unison. This is generally done by mating the electric motor to the engine where the transmission would normally attach, and then attaching the transmission on top of that. This allows the electric motor to take the power created by the gasoline motor and supplement it as it goes through the transmission and to the wheels. Though the concept is simple enough, the amount of manufacturing that goes into creating this set up is enormous; this is why the major automotive makers are the only ones that could attempt it. Not only do you need a electric motor than and mount to a combustion engine, but a transmission that can mount onto that electric motor, which is not something you can do yourself.

For this solution to work, you would have to find a complete hybrid system (from a wrecked insight, for example) and mount this system into another car. The major roadblock along this route is the idea that a Honda Civic Hybrid system was not built to be easily swapped into the body of a Honda Civic CVCC (a small civic last available 25 years ago). However big of a roadblock this is, it should also be considered that in the next method of building your own hybrid, mounting the motor and batteries will be done completely from scratch, so compared to the other options, having custom mounts built for a hybrid engine would not present and extra challenges. The next major obstacle is vehicle choice. When you add an EV system to a car, it is rather generic, as EV systems are not built by Honda, Toyota, or Ford. But, if you retrofit a hybrid system from a Civic to another car, the choice of car will be a big deal. For example, Honda builds specific to its cars, which means that it would be very difficult to take the hybrid system from a Honda Civic Hybrid and install it in a Chevy Nova chassis. This means that if you are choosing to move a newer hybrid system to another car, it would be much easier if the new car shared characteristics with the originally host of the hybrid system. Also important is the idea that your new car will share similar weight characteristics with the donor car. Swapping a hybrid system from an Insight, all though it is the most efficient, to a small SUV or station wagon would not be practical because of the weight difference.

Gas Powered Electric Vehicles

The most common solution to this problem, and the one that will most likely produce the best gas mileage, is the hybrid built as an EV with a supplementary gasoline or diesel generator. If you’re considering this approach, the absolute first thing you should do it pick up one or more of the books out there that detail the process of converting a gasoline car to an electric vehicle. Though it is not easy, you will learn that it is nevertheless doable. Though this article cannot cover the huge amount of knowledge that it would need to get you through the process of building a hybrid, there are a few things that are not “put this there” and “cut that here” that are extremely important. The first such thing is again, vehicle choice. Weight, storage capacity, and aerodynamics are extremely important, as these three things are the biggest limiting factors of EV range, and will also affect your hybrid’s efficiency the most. SUVs are not good choices because they perform terribly in two of these categories, even though they have a ton of storage area. VW Rabbits are reasonable choices because the have a good amount of storage for batteries and are very light, even if they aren’t very aerodynamic. Porsche 914s are also reasonable choice because they are both light and aerodynamic, even though there is not much room in them.

Somehow you will end up compromising on these characteristics when you go to build your hybrid, because model of car and ease of installation often outweigh optimum range or fuel efficiency. One of the best things about the Porsche 914 and VW Rabbit mentioned above is the ease of installation of an EV kit. This is because these two cars have kits preassembled for DIYers looking to convert to an electric vehicle. These kits eliminate the need to search around and collect parts, and also provide lots of help for actually building the car. Besides the practical benefits of these kits, the Porsche 914 is a fun car, and will definitely attract a lot of attention, whereas the Rabbit is a very common car that you can get in either two doors or four doors (for hauling around the family). While it is possible to convert many other cars, these two become the two easiest cars to convert to hybrids because of the availability of EV kits, which cut down on time spent collecting parts and also the level of customization that is needed to complete the project.

For this set up, the final component is the gasoline or diesel generator. For the car to be a hybrid, and not an EV, you will need to add a small engine the will spin an electric generator and recharge your battery banks. When picking your generator, you should decide a few things based on your motor and battery combination. Firstly, you need to figure out how fast your batteries are being discharged, and therefore how fast you will need to charge the batteries back up. If you can match your battery discharge rate relatively closely, then you should be able to travel on all electric for 60-70 miles, switch on the generator, and then travel many more hundreds off of the gasoline stored in the tank. This could really provide for a lot of range out of your hybrid, though for increase EV range and fuel efficiency you’ll probably want to keep a relatively low fuel level, unless you travel 100+ miles per day. The best thing about this method of building a hybrid is possibly the small size of the gasoline engine; it need only be enough to sustain the charge of the batteries. Some people have built hybrids this way with generators as small as 3 horsepower, and it would be unnecessary to go much over 20 horsepower as most cars only use 8-12 horsepower to maintain highway speeds.

What's next?

So what is the moral of this story? If you have ever thought about buying a hybrid, but you’ve always loved the classics, wanted your own style, or wanted to surpass the normal limits of fuel efficiency, you can do it yourself. For less than $18,000 you could even own a 30 year old Porsche that gets better gas mileage than any other hybrid on the road! In the world of self-created hybrid vehicles, your imagination is the only limit of the many possibilities. However, you can still build your own VW Rabbit of Porsche 914 hybrid in less than a week. The main thing is that you decide what will meet your needs and your wants, and to go from there. First you must decide what your goal is, then you need to research a means to complete your goal, and finally you just need to do it. It may be a long and complicated process, but in the end you’ll have a unique automobile that is great for the environment and that you can take an enormous amount of pride in.