Gas Versus Diesel, What Should I Buy? May 27, 2013
More and more today we're seeing cars and trucks with diesel engines in them. What was once an engine type relegated to semi trucks is more common than ever in passenger vehicles. There are people on both sides of the diesel vs. gas debate, and there are good and bad arguments for each. Let's take an un-biased look at this battle and see who comes out on top. I've split this up into five categories to get a good idea of which is better in the major categories. First off, let's look at initial cost. Initial Cost Diesel engines tend to cost more due to the higher compression ratios they tend to run at. This means they need to be beefier than your average gas engine. Basically everything in a diesel engine from the thicker block and heavier cylinder heads costs more. This means an overall higher initial cost for diesel engines verses their gas brethren. Winner: Gas Engine Fuel Along with initial cost, fuel cost, economy, and availability are important factors for overall cost as well. Diesel fuel has more potential energy stored up than gas does, with diesel having around 147,000 BTUs and gas having 125,000. This means you need more gasoline to equal the same power output of diesel. Thanks to direct fuel-injection that diesels use, less fuel is wasted as unburned. When idling, diesel engines use less fuel than a gas engine, which means even less waste. Overall, this means diesels are far more fuel efficient than gas engines. There is no clear winner in fuel cost, as the price of diesel and gas have been continuing to increase, making them near identical depending on the grade of gasoline you need to use in a specific engine. Generally diesel tends to be slightly higher in cost, but once again, this can even change dependent on the location. While more and more vehicles are using diesel fuel today, it is still far easier to find gasoline than diesel. Most gas stations in moderately populated areas and above will most likely have one diesel pump, but many smaller stations do not. This one definitely goes to the gas engine. Winner: Economy-Diesel, Cost-Tie, Availability-Gas--OVERALL: Tie Power/Torque When you think of diesel, one of the first things you probably think of is power. Diesel engines tend to have more torque than gas engines while gas engines generally have more horsepower. This is one of those deciding factors in whether you want a diesel or gas engine in your truck. Do you want quick starting and stopping or higher torque for towing? If you generally drive your truck unloaded and rarely tow, a gas engine would probably fit you best. If, however, you tend to tow frequently or routinely drive with your truck loaded down, a diesel really might be best. Once again, there is no outright winner here, but based on your specific needs, you will definitely have a winner. Winner: Tie Civility What I mean when I say "civility" here is how civil your truck is. Meaning, when you drive it through a neighborhood, do people wave hi or do they yell as you drive past? Depending on where you live and commonly drive, civility in a truck might be something you're looking for. When it comes to noise, the gas engine definitely wins out. They are overall quiet, reserved sounding engines that don't tend to bother too many people. Diesel on the other hand, are commonly loud and let everyone know where they are. Exhaust is another area that most people probably have a bias against already. Diesel exhaust definitely smells worse than gasoline engine exhaust, and diesels leave a LOT more particulate matter in their exhaust, which accounts for all the black smoke. This is getting better with advancements in diesel fuel, but overall, gasoline has much cleaner exhaust, even if it technically creates more per gallon of fuel than diesel. The last key element of civility here is cold weather starting and running. While gas engines don't necessarily like cold weather, and older non-fuel injected trucks required a warm-up time, you will generally not see too many issues from getting into a gas truck, starting it up, and going immediately on a cold day. This is not the case with diesel. Diesel engines require a warm up period to get them running smoothly. If the outside air is under 30* F, the air won't be hot enough to ignite the diesel fuel. There are computer-controlled fixes for this that change when fuel is injected into the cylinder, giving the air more time to warm up, and most trucks today have block heaters that let you get going quicker. Winner: Gas Maintenance If you own your truck longer than a year, a lot of this decision comes down to maintenance. How much does the truck cost to keep it running for years to come. I've split this up into short and long term, as they are pretty vastly different. In the short term, gas engines take the cake here. You need more of everything to keep a diesel engine running. From oil to lubrication, to filters, diesels cost more. In the long term, diesel brings home the win. Diesel engines are known for long term reliability. A typical gas engine will run up to around 115,000-125,000 miles before a major overhaul is necessary. Some go longer than this, but they are the minority. Diesel engines are made with semi trucks in mind. These big rigs can sometimes log 100,000 miles PER YEAR, not counting the days of idling they endure. Consumer diesel engines use this same technology, so you can easily expect 2-3 times the life expectancy of a gas engine for a diesel. Winner: Diesel Overall If you count the tally above, it looks like gasoline engines win. If you are on the fence on which to get, I think gas does indeed win, but the real winner here should be based on what you need out of your truck. If you plan on having it for a couple hundred thousand miles, and need to tow heavy loads consistently, get a diesel. If, however, you are looking for more of a daily driver than can get dirty when necessary, a gas engine might be for you. Think of all these areas before making your decision, but whatever you choose, make sure it fits your needs before you spend the money. Then, think of some upgrades to do, like basic off-road upgrades, including push bars, additional lights, and of course a train horn. Remember those costs before deciding as well, and you'll have the exact truck you want.