I noticed on the Tesla web site that the Roadster is rated at 302 hp. My owner's manual (2010) lists hp at 248. Torque is unchanged at 273 ft-lbs. I'm guessing that the actual horsepower has not changed, just perhaps the way it's measured? Or was there a horsepower increase from model 2.0 to 2.5?

Roadster Features and Specifications | Tesla Motors now shows 302hp for the base model and 299hp for the Sport model.

Isn't it more proper to finally switch to kW instead of HP when discussing EVs ? Nissan rates the Leaf at 80kW, not 109hp for example.

Yes, it is. And while we're at it, torque is measured in Newton Meters! Not in pound-feet.... The Model S for example has 400 or 600Nm of torque, that's not a coïncidence for being a nice round number. As far as I know the Roadster base model has 200kW of power max output, that's 700A of power. The sport has 900A of power at max, don't know how many kW's.

Early tests show the Roadster (non-sport) to have 248 HP. This is also what my VDS shows when I floor it. But Tesla's specification page states the HP is 302, just above the Roadster sport. Does anyone know if this is right? Other testing stated the lower 248 HP rating.

You have to have a standard to compare electrics to ICE's, HP seems the best way to do that. Regardless of gas, diesel, hydrogen, electricity, or wizard magic, any car can be put on a dyno and produce peak HP and TQ numbers and I think that's the way to do it. Obviously it's also useful to have the kW rating for direct comparison to other electrics but I'm willing to bet two cars with the same kW ratings can have different peak HP and TQ values. My $.02

Easily. Put two Model S vehicles next to each other at a stop light. One of them has climate control maxed out, the other doesn't. Both applying zero HP, but one of them has a higher kW consumption.

I'm not sure that's entirely correct. HP is measuring the same thing as kW, so two cars with the same HP will also have the same kW. But peak torque might vary between two cars with the same HP. It's also not very meaningful to compare ICE HP to electric HP. Electrics usually develop peak torque throughout their entire rpm range while ICEs don't. For example the Ferrari 599 has about 600 HP, more than 2x the Roadster's HP, but they both accelerate 0-60 at the same speed (actually the Roadster is usually quicker). So comparing HP between those two cars is not very meaningful.

Exactly. Its like saying yards are appropriate than meters. If you have Hp, multiply by 0.746 to get kW. If you have kW, divide by 0.746 to get Hp. Since more cars are rated in Hp than kW people in the general population (in the US) have a better sense of Hp than they do kW and will relate better to the Hp number. If you give them kW most will ask what's that in Hp to get a feel for the magnitude. However, in metric countries I expect the opposite is true. It should be tailored to your audience, so I would say it would be better to compare Hp in the US and kW elsewhere.