TRAVERSE CITY, MI – For the last few years, we’ve used our annual 250-mile (402-km) trek to the Management Briefing Seminars in Northern Michigan to test the highway-mileage claims of numerous diesel and hybrid-electric vehicles.

The results have been predictable: On our route, which is almost all open road and includes only a few miles of stoplights and “city” driving, the diesels usually meet or exceed their U.S. EPA highway ratings while the HEVs come up short.

This year we decided to test a gasoline direct-injected turbocharged powertrain.  

Small turbocharged 4-cyl. engines are taking the automotive world by storm as automakers seek to improve fuel economy by decreasing displacement and reducing cylinder counts without sacrificing performance.

On paper, the downsizing strategy has been a huge success, leading an EPA official to say recently that automakers actually are running ahead of current CAFE targets.

But many consumers have been disappointed by the mileage these engines deliver in the real world, mainly because even coming close to those numbers requires a very light foot. Using the turbo boost too much, too often, quickly erodes efficiency.

Our test subject is Volkswagen’s 1.8L EA888 turbo in the new Golf TSI, which hits dealer showrooms this month. The engine makes 170 hp and 200 lb.-ft. (270 Nm) of torque and replaces the 2.5L 5-cyl. base engine offered in the previous Golf.

While delivering power and torquecomparable to the outgoing engine, VW says the downsized EA888 provides a 20% improvement in highway fuel economy, a claimed 36 mpg (6.5 L/100 km) on the highway with an automatic transmission.

Because the new engine’s torque peak occurs at just 1,600 rpm, 2,650 rpm lower than the previous engine, and is consistent all the way to 4,400 rpm, the engine provides better acceleration, fuel economy and emissions than before, VW says.

WardsAuto tested a similar version of this engine – with only 184 lb.-ft. (249 Nm) of torque – late last year on the ’14 Jetta and named it one of 2014’s Ward’s 10 Best Engines, so we had high expectations for this more powerful version.  

And the engine does not disappoint. The ’15 Golf is the first U.S.-market VW based on the new MQB modular platform, and it is bigger all around in every dimension except height. The 4-door hatchback now can seat five (if one person is a child) and claims to have a larger “trunk” than any midsize sedan. We found the interior so roomy it almost seems too large to be a Golf.

Our test vehicle, a limited-edition, specially equipped Golf Sport model, weighed in at 3,023 lb. (1,371 kg). The car is up to 79 lbs. (36 kg) lighter than the previous model despite its larger size, but that’s still a lot of metal for a 1.8L engine to move. Even so, the EA888 launches the Golf strongly at throttle tip-in and pulls hard at every gear change. Freeway entrance ramps and passing on 2-lane country roads is a breeze.

The engine also is extremely quiet and vibration-free. When idling at stoplights, we found ourselves looking down at the tachometer to make sure the engine was running.

We conducted our fuel-economy test the way we always do. We topped off the tank and reset the odometer on our $27,750 test car (including $820 destination charge) in Grosse Pointe, MI, and pointed the nose north. We also vowed to drive the car conservatively, like a driver concerned about fuel economy.

That means we rarely drove faster than 75 mph (121 km/h), and kept it on cruise control as much as possible, but we did not resort to any hypermiling tricks or annoy our fellow travelers by driving 55 mph (89 km/h).

We did test the acceleration and high-speed-passing power on a number of occasions, but most of the time we stayed around 70 mph (113 km/h), the speed limit for most of the roads on our journey.

The result: We arrived at the Grand Traverse Resort near Traverse City with the trip computer reporting we averaged 35.2 mpg (6.7 L/100 km), just 0.8 mpg short of the official EPA number, even though the last leg of the trip has some significant hills. Given the miscalculations some automakers have made recently in their touted mileage numbers, and the fact this engine only had 2,631 miles (4,234 km) on the clock and is barely broken in yet, it’s a pretty impressive showing.

dwinter@wardsauto.com

’15 Golf Sport
Vehicle type 5-door, front-wheel-drive, 5-passenger hatchback
Engine 1.8L DOHC GDI, cast-iron block/aluminum head, turbocharged inline-4
Power (SAE net) 170 hp @ 4,500 rpm
Torque 200 lb.-ft. (270 Nm) @ 1,600 rpm
Bore x stroke (mm) 82.5 x 84.1
Compression ratio 9.6:1
Transmission 6-speed AT
Wheelbase 103.8 ins. (2,637 mm)
Overall length 167.5 ins. (4,255 mm)
Overall width 70.8 ins. (1,799 mm)
Overall height 57.2 ins. (1,452 mm)
Curb weight 3,023 lbs. (1,371 kg)
Sticker price $27,750 (including $820 destination charge)
Fuel economy 26/36 (9.0-6.5 L/100 km) city/highway
Competition Mazda3, Ford Focus, Mini Cooper Hardtop
Pros Cons
Refined exterior design Cool bodykit parts extra
More torque Disappointing exhaust note