Used Cars and Trucks: Gas or Diesel?
Used Cars & Trucks
10 years ago diesel engines on pickup trucks were smelly and noisy and shook like an overloaded washing machine. Today they are a lot more civilised, but are they better than gas engines? Too be able to answer this you need to understand each engine and also need to work out how you will use this truck as each engine is appropriate for particular duties. Let's look at the important criteria you will use to choose.
Power and torque sorry to sit on the fence here, but whilst gas engines produce more horsepower, diesel engines produce more torque. Do you want off the line acceleration? Do you want quick starts in town? Do you not usually haul a load or tow a trailer? If the answer is yes then you will be better off with gas as they rev up faster and can reach more rpm peaks than diesels can, which is why they have higher horsepower. But if you need brute pulling force and towing capacity then you want a diesel. The torque advantage is most suited for heavy loads. The relatively high compression ratio is necessary to ignite diesel fuel means that diesel makes its power and torque when it is on low revs.
Noise & Vibration Gas wins here. There have been huge improvements in engine noise technology and noise isolation in pickup trucks in the last 10 years, but diesels are noisier and shakier than gas. When they are idle, you will notice the shake and clatter of diesel trucks. It is also noisier when at low speed, but once you are running at normal speed there will be little difference between gas and diesel. Initial Cost Gas also wins here. Diesel engines have to withstand more punishment than do gas engines due to the high cylinder pressure and high compression ratios. Fuel Economy Diesel has the advantage here as diesel fuel has a higher energy density than gas does. So it takes more gas to get the power output of diesel. Diesel engines use a more efficient method of fuel injection than gas engines. When idle, diesel uses is 3 times more efficient than gas.
Short-term care Gas has the advantage diesel engines use a larger volume of oil and waster separators and fuel filters have to be serviced more frequently. Gas has extended service intervals.
Long-term care Diesel wins here it has excellent durability. You can use it to go hundreds of thousands of miles a year and haul very heavy loads. Gas engines need a rebuild after 125,000 miles.
Cold Weather Gas is the winner here. Diesel engines do not have spark plugs and gas engines do. So when its cold the air doesn't have enough heat for the diesel fuel.