High-performance luxury sport sedans can get good gas mileage - if they're diesels. BMW's new 335d, for example, gets highway mileage (36 MPG) that's as good or better than many subcompact economy cars. That's good for you. And it's good for BMW that the new 335d has virtually no competition because there isn't another car in its class or price range that also offers diesel power.

WHAT IT IS

The 335d is a BMW 3-Series sedan powered by a 3 liter,six-cylinder diesel engine. Base price is $43,900.

WHAT'S NEW

Diesel power is a newly available option (in the U.S.) for the 3-Series sedan. This is a "50 state" car, too - available everywhere and not just in a handful of states.

WHAT'S GOOD

Exceptional fuel efficiency for such a high-powered, well-equipped luxury sedan. Equally exceptional power/performance - zero to 60 in under 6 seconds. So smooth and quiet the only time you'll remember it's a diesel is when filling up. Same superb handling/driving dynamics as a regular 3-series. Some of the best seats on the market.

WHAT'S NOT SO GOOD

Mandatory automatic transmission with the diesel engine (gas-burning models all come standard with a six-speed). Sometimes fussy fuel filler system. $3,600 price hike over a 335i ($40,300). Diesel engine not available in wagons or coupes - or with AWD. Six gallon urea tank (used to lower emissions) must be topped off at every oil change.

ENGINES & PERFORMANCE

American drivers who have never been to Europe have no clue how far diesel engine technology has advanced since the '70s and '80s - the last time a significant number of diesel-powered passenger cars were available over here. Memories linger of feeble acceleration, horrendous clatter and ugly black clouds of soot pouring out of the tailpipe. Only a few diehards were willing to accept these drawbacks in return for the higher fuel efficiency and superior durability of diesel power. Understandably so.

The 335d will erase those bad memories forever - if you'll give it 5.9 seconds of your time. That's how long it will take for the twin-turbo'd, direct-injected 3 liter diesel six to get you to 60 mph. This powerhouse makes 265 hp and an astounding 425 lbs.-ft of torque - output comparable to a large displacement V-8 but without the big V-8's appetite for fuel.

At 80 mph, the engine is barely idling at 2,000 RPM. At 120, it is just beginning to stretch its legs.

A gas-burning 335i is slightly quicker to 60 and about as fast, all out - but you'll be stopping more often given its SUV-like 17 MPG city and 26 MPG highway.

The diesel is electric motor quiet on the highway and almost impossible to distinguish from a gas engine at idle. It even behaves like a gas engine - a big V-8 gas engine - with an RPM range that runs to 5,000-plus RPM (high for a diesel they typically max out around 4,000-4,500 RPM) and GTO-like off-the-line acceleration and part-throttle passing power.

RIDE & HANDLING/DRIVING IMPRESSIONS

The 335d handles and responds exactly like a gas-powered 3-Series, which is to say it is one of the most finely honed driving scalpels available. It literally carves up the road - and will make you feel like a pro as you effortlessly brush aside lesser machines. You have to drive a BMW to appreciate this. They really are that good.

What separates the 335d from the other versions of the 3-Series is that it is an automatic-only deal. You cannot get a manual transmission with the diesel engine. But you'll only miss the clutch if you don't test drive the diesel/automatic combo. The massive torque output (all of it available at just 1,750 RPM) is ideally suited for use with an automatic transmission because there's so much down-low/right-now power available. No need to rev it through the gears to extract acceleration. Touch the gas - and it goes.

STYLING & UTILITY

A 335d looks exactly like the gas-burning 335i, except for the different exterior badges. It is handsome, athletic-looking car. BMW has made a few slight changes to the exterior (front fascia, rear tail lights) and interior cosmetics but these have to be looked for to be noticed, compared with the '08s.

The dash layout is clutter-free and business-like. Most of the controls are immediately understandable and can be used without having to study the owner's manual or take your eyes off the road. The optional iDrive interface - which uses a mouse-like device to operate the GPS, audio system and other functions - is improved but still can be intimidating and/or frustrating to deal with. If you're a Blackberry or Kindle lover, you'll be fine. If you hate PDAs and other electronic gadgets - well, you'll probably hate the iDrive, too.

Driver and front-seat passenger accommodations are exceptionally good. Super-supportive (and super-comfortable) seats make being in this BMW a treat, even on hours-long rides. Back seats are equally comfortable but head and leg room is a bit tighter - which is a fact of life in a mid-compact sized car like the 3-Series. If you need to carry four large adults on a regular basis, you may need to move up to a size to the BMW 5-Series.

Unfortunately, that model's not yet available in the United States with a diesel engine.

Which brings me to one last point on the utility front. BMW wants to make absolutely sure you never put the wrong fuel into the 335d - including the wrong type of diesel fuel, such as "off road" diesel or diesel that isn't ultra low sulfur, which the 335d must burn exclusively to remain smog-compliant.

It thus has an unusual filler neck with an automatic-opening (and closing) stopper that prevents you from inserting any nozzle that's not up to snuff - diesel or otherwise. It's a good idea, of course, as the use of incorrect fuel can cause all sorts of problems from functional to emissions-related. But the filler is fussy - or at least, it was on my test car. I was unable to fuel up at one station despite my best efforts. The pump was the right pump, from what I could tell. Maybe i was just doing something wrong. I never did figure it out - and luckily had enough left in the tank to try another station where things worked out ok.

Still, there may be bugs to work out - so, be advised.

You'll also have to periodically refresh the urea tank - a storage container for the urea that is used to help keep the BMW's emissions within today's uber-strict requirements (including California's). This is done at each oil/filter change, or about every 10,000 miles. The urea costs about $4 per gallon and the BMW's tank holds about six gallons total.

There is a warning light in the dash that lets you know if you run low on urea before the scheduled maintenance. Pay attention if it does come on because if you let the tank run dry, eventually, the car's electronics will disable the ignition to prevent the engine from being operated without urea - which could harm the emissions controls or increase the car's emissions output beyond acceptable levels.

QUALITY & SAFETY

Top drawer in every respect. BMWs are known for their typically German "put-togetherness" - and the 335d is no exception. Beautiful paintwork; tight fitment of all panels. Interior panels all have a high-end look and feel. Creamy leather; solid feel to all switches and controls.

Good warranty, too - four years/50,000 miles for everything. And a generally better-than-average rate of depreciation. The diesel engine, properly cared for, ought to be capable of going for 300,000 miles or more.

In addition to ABS (and excellent brakes), side-impact and curtain air bags, traction and stability control, the 335d comes standard with run-flat tires, which means you may never need to risk your life changing a flat on the side of a busy Interstate.

The 3-Series sedan scores at or near the top of its class in government and insurance industry crash testing.

THE BOTTOM LINE

A very tempting alternative to a gas-burning 3-Series sedan. It's just too bad the diesel's not offered with the 3-Series wagon, especially - where it would arguably make the most sense.

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www.ericpetersautos.com or EPeters952@aol.com for comments.