DETROIT — We like to do extended evaluations of a couple of each year's new Ward's Ten Best Engines winners, because we think it adds perspective that's not always available from the 10-day tests during the Ten Best Engines competition itself.

But in our long-term evaluations, it helps if something happens to talk about, something to perhaps balance the superlatives we've already heaped on the winning engines.

With Audi's insouciant 1.8L DOHC turbocharged I-4, nothing's happening to even remotely change our minds. To the core, this is a brilliant engine, brilliantly executed. In the just more than 20,000 miles (32,000 km) we've accumulated in a scant six months, the 5-valve-per-cylinder 1.8L hasn't missed a step, always revving with abandon and delivering surprisingly good fuel economy (see spec box) despite the all-too-frequent runs to the redline the Ward's staff finds so rewarding.

More than anything, this engine is testimony to the advantages of light-pressure turbocharging when developed and executed with absolute perfection. Although 170 hp and 166 lb.-ft. (225 Nm) doesn't sound like much — particularly, perhaps, for a premium-nameplate car — Ward's typically power-starved staff never finds this engine wanting, largely because the turbo always seems to be lurking in the background, ready with whatever amount of forward thrust is required, virtually regardless of engine or road speed.

And as we mention above, those five tiny valves pumping away for each cylinder must have highly optimized mass, because this little Audi powerhouse revs with the sort of low-intertia feel plenty of sports-car engines can't replicate.

We're also delighted with the general deportment of the entire driveline: the 5-speed manual transmission, although its gearshift can run towards spongy at times, is a delight, while being hooked to Audi's quattro — still our favorite all-wheel drive (AWD) system — doesn't hurt when it comes to laying down peak torque at engine speeds as low as 1,950 rpm.

Meanwhile, Audi's excellent “Advantage” no-cost scheduled-maintenance plan (4 years/50,000 miles) has meant just that: no cost. We haven't spent a dime to maintain this car for 20,000 miles, and it's asked for nothing outside of the scheduled services except replacement of a prematurely fried bulb in a rear signal cluster.

We're convinced this is a great engine in a great package. Everyone who drives Audi's A4 wagon returns smiling, impressed with the engine and impressed with how much this tidy package can swallow.

Perhaps art director Susanne Scott summarizes best when she writes in the A4's logbook: “A very pleasant car. I find the engine responsive and very easy on fuel: I got about 30 mpg (7.8L/100 km) at a steady 75 mph (121 km/h). And it's a nice-looking car, both on the exterior and the interior.”

Others echoed Ms. Scott's comments, adding things like: “Step on it at almost any speed and it just goes and goes and goes,” and “Very quiet car with a deceptively powerful engine. Gas mileage, too, is phenomenal.”

So far, the only complaint comes from long-distance haulers who think the gearing leaves the engine running a bit too fast at higher speeds. At 85 mph (137 km/h), the 1.8L turbo engine's turning around 4,000 rpm and is quite throttle-sensitive. A tall, highly overdriven sixth gear would take care of that.

2001 Audi A41.8T Avant quattro
Engine: 1.8L (1,781 cc) DOHC I-4; aluminum block/aluminum head
Horsepower (SAE net): 170 @ 5,900 rpm
Torque: 166 lb.-ft. (225 Nm) @ 1,950 rpm
Compression ratio: 9.3:1
Specific output: 94 hp/L
Date delivered: 4-11-01
Total miles/miles covered in this report: 20,527/12,323
Overall MPG: 28.1
Total maintenance cost: $0
Non-scheduled maintenance total: $0