rockville

Yes, I think many would use those terms interchangeably. I would myself. However, I think the terms come from different origins and thus the originators of the terms might have seen them as different. I think the monocoque term was born out of the racing world referring to a folded aluminum panel structure that was built using methods similar to aircraft (rivets and glue). It carried the structural loads of the car via the surface of the panels.

Unibody comes from bringing the car's chassis and body together into a single structure. The construction methods of a unibody aren't much different than that of the body part of an existing car of the time. The bodies (which provided much of the chassis's rigidity) were constructed of parts stamped from flat steal and welded together. The difference being with the designers had to have a better idea how strong those stamped-welded parts really were.

Thus the "difference" I see is the monocoque started with aluminum riveted and glued airplane construction and then moved to low volume race cars while the unibody was an extension of the high volume body building methods already employed by the car companies. Both achieve basically the same objective which is carrying loads through the surfaces of panels vs through bulky, load bearing structures. Anymore I would say both are the same thing but we have the different terms because they came from different places.

912S2k

The only issue I have with the new Raptor is that it sounds awful.

mosesbotbol

On unibody cars, the outer panels are structural, on the monocoque cars, it's just the frame, tub, etc... that is doing the work. The outside is just a shell.

912S2k

That isn't correct. Most of the body panels on a unibody and a monocoque are non structural. The difference between the two is the front and rear crash structures on a monocoque are usually metallic and secondarily bonded or fastened to the monocoque foabilityability ans cost. The only body panel that I can think of that is semi stressed is a roof panel and typically that has a triangular structure underneath it that transfers the load between the windscreen structure and the B or C pillar structure. I'm sure there are variations on cars so take this with a grain of salt but this is true for 75% of all automotive structures.

LUV2REV

So does the F80 M3/M4, Nissan GT-R, BRZ/86 which can be rectified through the aftermarket, likewise with the new Raptor.

rockville

I see the distinction you are trying to make but I don't think it's really true. As I noted above I don't think the terms are really considered different anymore. Anyway, I don't think monocoque's have to be made from metal. I think the current Indy and F1 cars are considered monocoque and they are carbon tubs. Also, when the carbon tubs were first introduced they were sometimes called black aluminum because they basically replaced the aluminum honeycomb panels with carbon honeycomb panels. I suspect someone might have a "pure" definition that distinquishes between the two but anymore I think we are dealing with AWD vs 4WD. These terms blur together as just as the structures blur chassis types.

BTW, to be that jerk who has to prove himself right I tried to find the terms in some engineering based books.

https://books.google.com/books?id=s1...ocoque&f=false
https://books.google.com/books?id=m5...ocoque&f=false
https://books.google.com/books?id=NS...ocoque&f=false

budgy

I don't think from reading his post that he was saying monocoques have to be made of metal; more that typically they are made of other materials such as carbon but they use metal crash structures bolted to the monocoque, most carbon super cars use this method as far as a I know.