Boston.com's view

The roadster, perhaps the purest form of sports car, endures, even as it seems to be ceaselessly tweaked. Take the latest version of the “entry level” drop top in BMW’s Z3 stable, the 2.5i. We have come a long way from the days of the beautiful 507.

When last we tested a 2.5, it was called a 2.3 – a complication of nomenclature that belied the fact that the 2.3 did, in fact, have a six-cylinder, 2.5-liter engine. That one produced 170 horsepower and was a respectable little zipster on the road.

It sure was an improvement on the original four-cylinder, 1.9-liter engine it replaced. Now comes the 2.5i engine, tweaked to produce 184 horsepower. It’s not the M Coupe, but what is?

The result is that the 2.5i is quite zippy on the highway, fast as you need to go on country lanes, and capable of turning 0 to 60 miles per hour in under 7 seconds. And it is fun to drive, with its short-throw five-speed manual transmission remaining crisp and precise up and down the gears. A five-speed Steptronic automatic transmission is an option.

This is not a car that will run with the Porsche Boxster S or the Honda S2000, but if you’re looking among the Toyota MR2, the Mazda Miata, or the Mitsubishi Eclipse Spyder, this car, even at a few thousand dollars more, ought to be on your to-check list.

The changes since the 2.3 are mostly engineering changes, which means that the muscular front, with its humped fenders, remains. Also surviving are the great rise and flare that was added to the rear, an aesthetic improvement on the angular box of the original car.

Again, it is no rocket, but it is very quick. Start to 80 miles per hour comes very quickly – and arrives to the accompaniment of a burbling exhaust note. A downshift on the highway from fifth to fourth turns the Z3 into a frolicking accelerator, able to scoot nimbly through traffic as it handles lane changes in a stiff, sure manner.

On back roads, just as its predecessor performed, it clung as if it were stuck to rails, exhibiting little body roll and virtually no evidence of body torque often found in convertibles.

Having just emerged from a couple of larger convertibles that shook, rattled, and rolled more than I could live with, this was refreshing. Even when hitting the stiffest of bumps, cowl shake, while evident, was well dampened.

The suspension features gas struts up front, semi-trailing arms and shocks in the rear, and antiroll bars in both places, and gives the car the stiffness you expect and need in a quick little sports car. Add to this Dynamic Stability Control, which uses engine power and braking to control wheel slippage, ABS, and a limited slip differential, and you have an easy car to control.

That said, I still do not think this is the ideal car for winter driving. It is rear-wheel-drive and a little too quick with those rear wheels to perform well in the snow.

It also sits quite low to the ground, so getting to the ski house could be problematic on a snowy night. Not that you could carry your skis and gear anyway. Interior space is minimal – none behind the seats – with shallow bins in the doors and a center console bin that would hold a cellphone only because technology has shrunk the phones. The trunk would hold no more than a pair of gym-bag-size travel cases.

In the months you can travel effortlessly, you will do so in snug, secure comfort. The leather seats plop you down low and wrap you firmly along the legs and up the torso. Cavernous forward space for the legs is an advantage while a somewhat low roof could be a problem for taller drivers.

Safety equipment includes driver and passenger front air bags, door-mounted side air bags, and roll bars.

The premium and sports packages that came with the test car included 16-inch cross-spoke alloy wheels, leather upholstery, wood trim, and power operation for the convertible top.

Is this the car for the true performance enthusiast? Probably not.

Is it the car f people who want a full-blown classic roadster feel and just a taste of where performance can take them? Absolutely.