A common question we get, is: "What's the difference between the belt drive and direct drive pressure washers?"
First of all, all of the motors are going to be the same which are Horizontal Shaft motors.
The Direct Drive setup, marries that shaft directly into the pump. The pump doesn't have a shaft, but instead gains it's rotation directly from the motor. If you want an example, there's a good video on Asphalt Sealcoating Direct that shows a low pressure banjo pump being married to a honda engine. You'll find the video towards the bottom of the description. It's not pressure washer related per-say, but gives the base idea of how direct drive and pumps go together.
Belt drive pressure washers, have a pully on the shaft and the pump also has a shaft with a pully. There's a belt between the two pullys.
So what's the difference? Really?
There's pros and cons to both setups and depnding on what you plan to pressure wash, should help you decide which setup is best for you.
Given all things equal, the two worst enimies of a pressure washer pump are heat and excessive vibration.
Direct Drive Pros & Cons
Since the direct drive marries the pump and motor together, you end up with a smaller footprint between the two. This allows manufacturers to create a smaller chassis for the pressure washer and thus, saves on weight and space. The downside to this setup is that you end up with the pump that is directly next to the motor. Since heat is bad for pumps, the heat from the motor will decrease the lifespan of the pump. Keep in mind that pumps get hot on their own due to the friction of pressurizing the water, but when you put the pump right next to the hot motor, it makes it that much hotter. In addition, the pump and motor have to be on the same plating which means the manufacturer can't really do a whole lot to reduce vibrations. Overall, the direct drive units will have a shorter maintenance window on major parts, but little to no maintenance in-between.
You might say that a direct drive pressure washer is the worst you can get and when you look at the cons, it does look that way! But, keep in mind, it all depends on what you're going to do with your unit. If you're only going to use a pressure washer a few times a month, or even a few times a week, you might be better off saving the space and having a lighter pressure washer. The heat and vibrations will take a long time to affect your pump.
However, if you're going to use the pressure washer on a daily basis, or multiple times per week, you might want to go with the Belt Drive pressure washer.
Belt Drive Pros & Cons
Belt drive pressure washers usually have the pump about 10" to a foot away from the motor and sometimes have rubber grommets to reduce pump vibrations. This helps prolong the life of the unit. However, the separation of the two means you end up with a larger power washer chassis. If space is the main issue, you may not want to go with the belt drive option. If space doesn't matter and a longer lifespan of the pump is more important to you, then the belt drive is going to be the better route over the direct drive. In comparison to the direct drive, you'll have more small maintenance tasks with the belt drive like replacing belts or tightening the belt, but you should get better longevity between major maintenance windows.
The main takeaway is that you should purchase a pressure washer based on what you're going to do with it, whether you need a smaller footprint, or whether you do or don't mind dealing with minor tinkering tasks. If you're a home-owner or business owner who only plans to pressure wash a few times a month, it might be easier to just go with the smaller direct drive units. If you're a contractor and powerwash or sandblast with a pressure washer for a living, you'd be better off going with the belt drive units.