When it comes to sports sedans, BMW wrote the book with its “3” series.

These small, swift compacts always combine sports car manners with sedan accommodations.

Of course, their price is another matter. As the stickers swelled, BMW responded with less expensive versions featuring a 1.8-liter four-cylinder. These cars have all the handling characteristics of bigger BMWs, but they lack a little in the motivation department.

Enter 1998.

BMW has replaced the 318is coupe and convertible with the 323 coupe and convertible. The 318 sedan and hatchback remain as four-cylinder automobiles, while the 323 gets a brand-new 2.5-liter engine that used to power the 325i, which was replaced by the 328i. The bore of the 2.5-liter engine is shared with the larger 2.8-liter engine found in the 328i, but it has a shorter stroke. This means the 2.5-liter has less horsepower than the 2.8 — 168 vs. 190 — but much more than the 1.9-liter four-cylinder (168 vs. 138).

That’s more than sufficient to move this coupe to 60 mph in 7.1 seconds with a manual transmission or 8.2 seconds with the automatic. Moreover, the six is an in-line design, very smooth and well behaved.

It growls with authority, adding to the car’s sporty handling characteristics. This is a true sports sedan that never sedates its driver into numbness as so many Asian luxury cars do. This auto reminds you of its machine-like character. You always hear the engine’s lovely note, feel the road surface’s characteristics. The steering has a weighty, natural feel to it that isn’t hidden by a power steering pump.

What does all this mean?

It means this car is a hoot and thrill to drive, the most fun you can have with your clothes on. Unlike some sporty machinery, it’s so deftly balanced you never tire of it.

The 323is comes with 205/60R-15 H-rated tires with alloy wheels, which can be upgraded to 225/50 ZR-16 tires as part of a new sport package, an option the test vehicle did not have. The package also includes fog lamps and sport suspension. Another available package, the Premium, offers a sunroof, keyless entry, leather seating and a folding center armrest. Try the base coupe before deciding if you really need either.

Inside, the driver is treated to a firm bucket seat with the perfect driving position. Despite lack of a tilt wheel, the ergonomics are good. The audio system is quite good and includes a cassette player and weather-band radio. An upgraded stereo by Harman Kardon is available, as is a six-CD changer.

The back seat offers room for two and is more commodious than most coupes. The 9.2-cubic-foot trunk is roomier than its numbers suggest.

Safety is well taken care of, with dual front and side air bags. Four-wheel anti-lock disc brakes and traction control are standard. The brakes are powerful, providing short, controllable stops with little fade. The traction control was a boon in bad weather, making this car much more adept when moisture mars the day.

While the 323is test car had such luxuries as dual climate control, it lacked keyless entry, sunroof, auto-dimming rear-view mirror and heated seats, but all except the mirror are available as options.

However, the real luxury here is the superb driving experience you get in a car that starts under $29,000. The test car stickered at $28,700 plus destination and optional equipment.

The most shocking part of this superb coupe is the real bargain it is. For just $1,000 more than the old four-cylinder coupe, BMW antes up two more cylinders. This makes it the least expensive six-cylinder BMW in five years and undercuts arch-rivals Mercedes and Audi, who offer only four-cylinder sedans in this range. Lexus and Infiniti both have six-cylinder cars, but they aren’t as athletic or as fun as this one.

With great handling and accommodations to handle extra passengers and their cargo, this little coupe is a real co p — one that merits a close look for any enthusiast in this price range.

What a Bavarian blast!

1998 BMW 323is Standard: 2.5-liter double overhead cam in-line six-cylinder engine, four-wheel anti-lock disc brakes, traction control, alloy wheels, dual front and side air bags, power heated outside mirrors, intermittent wipers, dual automatic climate control, AM-FM-cassette-weather band 10-speaker stereo, six-way adjustable front bucket seats, power locks, power windows, leather-wrapped steering wheel and shift-control knob, cruise control, clock, temperature display, leatherette upholstery. Options: automatic transmission, fog lights. Base price: $28,700 As tested: $30,505 EPA rating: 19 mpg city, 27 mpg highway Test mileage: 21 mpg