What is the difference between 4wd and awd?
The Subaru All-Wheel Drive is available in both automatic and standard transmission versions. The Subaru automatic transmission with All-Wheel Drive uses a set of transfer clutches and a solenoid controlled by the transmission control module (TCM) to engage the All-Wheel Drive system. In a Subaru manual transmission with All-Wheel Drive what is found is a viscous coupler that engages the All-Wheel Drive system. Some of the key points of service and maintenance with either design is to change the transmission fluid on a regular basis, keep the tires properly inflated as well as ensuring that the tires have a similar amount of tread and tread design all the way around. Some of the things on the never do list would include towing the vehicle with the wheels on the ground, coasting the vehicle with the engine shut off, and most importantly driving the vehicle with the space saver spare tire on it for a longer distance than specified by the manufacturer.
All-Wheel Drive is a superior mode of traction in my opinion to that of a vehicle with 4-Wheel Drive. The All-Wheel Drive system is better equipped for ever changing road conditions and is a great safety feature. But not every All-Wheel Drive system is the same. The Subaru stands alone design and function. While a lot of the newer system’s being put in vehicles of every make have a lot of fancy features and names, they all seem to lack the basic design principle that makes the Subaru system superior. Regardless of how many electronic controls you through at an All-Wheel Drive system if the mechanical aspects of the system are not symmetrical the system wont be as good as one that is. One of the advantages Subaru has with the Boxer engine platform is the ability to keep the drive train centered in the vehicle and the axle lengths the same which creates better function.
4-Wheel Drive is usually engaged either by mechanical linkage or some form of actuator either vacuum or electronic. One of the problems with this design is that due to the mostly mechanical nature of the system it doesn’t really posses the ability to adapt to road conditions as quickly as an All-Wheel Drive system can. With All-Wheel Drive you have the traction you need when you need it. With 4-Wheel Drive you have to engage the system when you need it and disengage it when you don’t. Sometimes when hitting an ice patch there is much to think about and it can be hard to remember to engage the 4-Wheel Drive system. When driving through a corner in the rain, All-Wheel Drive is really the only system you want to have.