Trains are what make money in railroad tycoon 2. Track and stations do nothing on their own. The choice of locomotive can make or break a company, so one of the key important things is to choose a locomotive which will hopefully maximise your profts. Profits of course are the difference between revenues and costs, so you are looking for features which improve your revenue, and low costs, and usually it has to be some comprimise between the two. Below is a list of features and how to use them.

• Cost: The initial cost of buying the locomotive. Generally speaking, in its lifetime a locomotive will make enough money to pay for the initial cost several times over, as a result cost differences aren't too important. However, when starting up a company, you can buy more trains if you choose cheaper locomotives, although sometimes it is better to pay extra and have more profits per train rather than more trains.
• Speed: This is the top speed the locomotive was designed for. Typically it won't quite ever get to this speed, because it will have a load which slows it down, along with gradients. A higher top speed increases revenues earned, dependent on what type of cargo it is, especially so with passengers and mail. Also a higher top speed allows the train to make more trips in a year. So a high top speed is desirable.
• Hauling Index: For each locomotive I have calculated the deviation from its top speed. A high figure for the hauling index implies that the locomotive can pull a heavy load without it slowing down much. If it has a low figure, then it will be slowed down considerably by loads, and you should only therefore use only two or three cars.
• Grade Index: This is similar to the hauling index. A low figure implies that a grade will greatly slow down a locomotive. However, if this figure is high then that implies the loco won't be slowed down much.
• Acceleration: This is the measure given in railroad tycoon 2 of the how long it takes for the locomotive to get to its top speed from standing. Remember, every curve in a railway a train must slow down. If your railway has a lot of curves, or grades, then acceleration is important otherwise your train will always be running at far less than its top speed, as it doesn't have enough time to accelerate before hitting the next curve. This ranges from best to worse: Extremely Poor, Poor, Below Average, Average, Above Average, Fast, Very Fast, Virtually Instant, Instant.
• Reliability: This is a measure of the chance of breakdown. A loco with poor reliability is more likely to break down than one with good reliability (all other things being equal). Although this may not be too important, when you have a busy railway, then it is a good idea to make sure all your trains are reasonably reliable because if one breaks down it can delay the rest of them.
• Maintanance Costs: These are the annual costs of running a train. They are fixed, irrespective of how much your train is going to be used. So if you are buying a locomotive for a short distance run where the locomotive may be sitting waiting for cargo for a long time, try to look to minimise this cost.
• Fuel costs: These are the average annual fuel costs of running a train. They are variable, according to how far your train runs. So if your running a long distance route then you should try to look to minimise fuel costs.
• Available: This gives the year in which the Locomotive becomes available
• Withdrawn: Eventually, most locomotives become obsolete and are no longer available for purchase, after the year shown.
• Type: This tells you whether the engine uses steam, diesel or electric propulsion. Note that if it uses electric propulsion you will need to have electrified track.

In choosing a locomotive, you need to balance out things that might yield high revenues, such as a high top speed and high power, against the running costs of the train. Generally, trains with a low top speed and power will have low running costs. These will usually make modest profit. Trains with a high top speed and power tend to have high running costs. Depending on circumstances, these trains will either make massive profits, or massive loses, so be very careful.