if we look at high performance sports car,we can see most of their engines at rear portion but as usual cars we see engines at front portion…except from normal cars what kind of benefit do the rear engine cars give us???..like lamborghini,audi r8,posche 911,bugatti veyron
They are rear wheel drive with the weight of the motor over the drive wheels for traction, best of both worlds but a packaging nightmare.
It is all about weight distribution. Best handling is achieved with 50% of weight on front wheels and 50% on rear wheels. The engine is the heaviest item in the car, so where you place the motor has big impact on weight distribution. Many race cars and sports cars try to get the motor in the middle of the car. Not a great place if you want a trunk, storage space, and room for passengers; but great for handling at high speeds.
Uncle Turbo is correct.
I agree with all of the above, but it is important to clarify exactly what is meant by “rear engine”.
Nowadays, carmakers realize that putting an engine too far to the rear will result in extreme oversteer.
For instance, the Auto Union race cars of the 1930s had HUGE engines placed behind the rear wheels. In terms of straight-ahead traction, they were incredible. The problem however, became obvious on curves, with the result that a very high percentage of Auto Union’s professional racing drivers were killed in oversteer-induced crashes.
If we go to the late 1940s, the Tucker Torpedo (of which only about 50 were produced before the company went bust) had a large, high torque engine mounted behind the rear wheels. Although not enough of them were ever produced to produce a wide-spread safety issue, I believe that if these cars had gone into series production, there would have been a lot of deaths as a result of oversteer–which former drivers of understeering Front Engine/RWD vehicles would have been unable to cope with.
Then, as recently as the 1960s. GM’s Corvair also had the engine mounted behind the rear wheels. Like those earlier Auto Union cars, their straight-ahead traction was incredible, but on a slippery curve, many owners were unable to cope with the sudden oversteer, thus resulting in accidental deaths.
The shame of it all is that GM could have ameliorated these problems in two ways:
Instead of the cheaper swing-axle with which the cars were equipped, if GM had installed an articulated rear axle with two U-joints instead of just one, the increased amount of tire contact on curves would have reduced much of the oversteer problem. Only in the last-generation Corvair did GM spend a few bucks more for a better rear axle/suspension design.
And, the most highly-publicized problem with those early Corvairs was the reality that the cars needed drastically different tire pressures in the front and rear tires in order to prevent vicious oversteer…something along the lines of 16 lbs front and 28 lbs rear–or something to that effect. The information on the vitally important tire pressures was buried in the Owner’s Manual, rather than being prominently displayed on a label on the door jamb or inside the glove box. For owners of the more conventional cars of the day, it was typical to use 26 lbs all-around, and that was a potentially fatal error with the Corvair.
But, to get back to my point, what is frequently referred to nowadays as “rear-engine” is actually more akin to a mid-engine design, with the engine mounted either just in front of the rear wheels, or directly over them. This is, indeed, a packaging nightmare, but it tends to produce incredibly good traction and handling–unlike the older designs where the engine was placed in back of the rear wheels.
I agree with the Corvair statement completely. I owned one back in the mid-sixties and I can tell you that there was no advantage to having that engine in the rear. At slow speeds it was not too much of a problem but at higher speeds I had a tough time going around the slightest curves. Add a little rain or snow and it was next to impossible to keep the little oil burner out of the ditch. This was a 30k car that was only 3 years old.
For some reason American drivers seem biased to understeer and the Corvair’s oversteer, in its original design, was a disaster when sold as a family sedan. And GM went so far as to build a Corvair wagon. The car was a lot of fun to drive in its day and the pickup version might have been a workable vehicle but the entire concept was trashed by “Unsafe at any Speed.”
Rod–The Corvair station wagon and the van version had an additional problem.
Because the engine was–literally–inside the passenger cabin, and because the heater boxes tended to rot out after a few years, exhaust fumes would seep into the cabin, with sometimes disasterous results. I vividly recall the case of a carpenter who used one of the Corvair vans for work, and he was turned into a brain-damaged vegetable by long-term CO exposure.
Also–the maximum payload of the pickup and the van was greatly reduced by the weight of the rear engine. Having a rear engine in a vehicle designed to carry large loads in the rear is…not a great concept.
All-in-all, not a good design.
My experience with the Corvair pickup was delivering groceries in a small town, VDCdriver. I doubt that I ever exceeded 45 mph but it seems like at the time it handled much easier than the GMC pickup that it was replacing. The worst complaint that I recall from owners was belt failures.
Rod–For local grocery deliveries, it was probably a good vehicle.
Corvairs were known for very light steering, so it was probably a pleasure to pilot–as long as you kept your speed down. And, those drop-down ramps on the side were an excellent idea.
Just be glad that your employer used the pickup version, rather than the van version!
hmm…but xperts say that the gravity centre of a car is at the mid-rear position,as a result,there might not be so problem…but i don’t know very well about that
It’s more than achieving 50/50 weight distribution. A front engine car can have a near 50/50 weight distribution as well (eg, BMW). Mid engine cars concentrate their weight in the middle, allowing them to easily change direction. Try to hold a heavy dumbbell with the weights on both sides of your hand and rotate it. Then try to roll it on the ground. The dumbbell would have even weigh distribution in both rotation modes, but the latter method will be easier to spin.
The disadvantage of a mid engine car is that it is easier to change direction. It is a double edged sword. If it spins, it just snaps into a spin instead of breaking away gradually like a well thought out front engine car and is harder to recover. For a race car designed for the sole propose of winning a race, this is the way to go. Otherwise, snap overseeing is not desirable on public road
Most of the cars you mention are mid engine. The 911 is a rear engine and the Corvairs that everyone else mentioned are rear engine. In a mid engine, the engine is behind the driver but forward of the rear axles. The rear engined cars are best on snow and ice, the mid engine cars are capable of the best handling, but in both cases, they are tricky to drive and if you are not trained in them, you can get into serious trouble quickly. Not good for average drivers.
Most of the cars you mention have mid-engine cars. They are behind the driver and in front of the rear wheels. The 911 is the only one with a rear engine.
I agree, Keith! I just didn’t see your first sentence.
Seems to me that the best-designed rear-engine car was the old-style Volkswagen Beetle, with its air-cooled “pancake” 4-cylinder engine just behind the rear wheels. I’ve heard a number of people say how well a VW Bug could plow right through a snow-covered street while front-engine RWD cars would have a lot of difficulty getting traction. Apparently GM couldn’t make the Chevy Corvair to be as reliable as a Bug, and that’s probably one of the reasons why the Corvair was discontinuead after 1969. My own personal experience driving a rear-engine vehicle was when I’d drive my dad’s 1974 VW Westfalia pop-top camper bus; it’s what I learned how to drive a stick shift on, too, at age 15. And speaking of rear engines, Motorcoach busses (i.e. Greyhound) and bus-based motorhomes have had rear-mounted engines for decades.
Garagtop…packaging for rear engine cars is indeed a nightmare. While resorting to storage in the front, you change the handling dynamics significantly, loading it up with golf clubs. Not nearly the big change when throwing weight into a rear trunk. The only rear engine vehicles that seem to be immune from throwing a little extra weight in the front, is a bus.
A rear engine also moves more noise away from the driver.
This is as simple as they get these days.
“what is the advantage of a rear engine car???”
Traction, especially under adverse driving conditions at normal driving speeds…Also, it allows stylists a free hand with radical front-end configurations including very aerodynamic ones…
But once balance shifts past 40-60 front-rear, high-speed handling begins to suffer and special driving skills are required to maintain safety…