phenoyz, it depends which model year you are looking at. Regardless of MY the difference is 50 hp. However there are several other differences as well. Several people have said they like the base model because it forces you to work harder to go fast, and given the engine's smaller size it's a bit more rev happy and needs to be kept high in the rpm band. On the other hand the vast majority of Porsche-philes will recommend always purchasing the newest model year S you can afford (that advice is as old as time).

The 987.1 (MY 2006-2008) Cayman has a 2.7 liter engine with 245hp. The Cayman S of that vintage has a 3.4 liter engine with 295hp. The Cayman has a 5 speed manual transmission - the S model a 6 speed manual. The base Cayman has 17" wheels standard, the S 18"s. The S also has considerably larger brakes with red painted calipers and a "dual" exhaust outlet.

The 987.2 (MY 2009-2012) Cayman has a 2.9 liter engine with 265hp. The Cayman S of that vintage has a 3.4 liter engine with 315hp. The base Cayman still had a 5 speed transmission standard, but I believe the 6 speed box was an option. And everything else I stated above applies to these model years, AFAIK.

While doing research for a potential Cayman purchase I would recommend the online community over at www.planet-9.com

OP probably wanted a car that worked most of the time and was actually comfortable.

Thanks.

BTW I was slightly off on the hp figures...The 2009+ Cayman S has 320hp, not 315. Sorry about that.

I think the 315 was the rating of the 987.2 Boxster S, if I remember right.

Yeah I think you're right. Though I thought the difference between Boxster and Cayman was bigger than 5hp, more like 15? Eh whatever :P

Those numbers are all BS anyways. I had the Cayman R which was supposed to have 330 hp, but the dyno results didn't show that.

The 330 is specified at the crank, so unless you know the drivetrain loss, you can't really say whether it was BS or not based on a dyno graph.

You can when you compare it to Cayman S dynos.

Fair enough (though it is always possible that the S is underrated and the R is accurately rated).

Do rear engine Porsches experience less drivetrain loss compared to FR cars? (cause no driveshaft..?)

I believe so, in the same way that a FF car has lower drivetrain loss.

The Elise has a reliable Toyota drivetrain, haven't heard of issues with the 2zz.

A lot less powetrain loss, basically they have more in common with FWD. Look at the MR-S (2), Toyota raided their fwd parts bin to build that car and it had much less powertrain loss than our twins.

But its much easier and cheaper IMHO to work on FR.

Rear and mid-engined Porsches do not have much if any less drivetrain loss vs. front-engine/rear-drive cars.
There is pretty much *zero* power lost in the driveshaft of an FR car. Losses throughout the driveline are primarily the transmission (two gear interfaces at ~2% each) and the diff (ring and pinion at ~6%) and the tires accounting for another ~5%.
These same losses are all present in Porsches.

A big advantage of transverse-engine fwd (or transverse mid-engine like the MR-2) is the lack of a ring/pinion. 6% r/p loss replaced with a chain or gearset at 2%, so roughly 4% more efficient vs. longitudinal engine with a ring/pinion, all else equal.