Our long-term 2017 Mercedes-Benz GLC300 4Matic has been with us for a few months now and although things have gone smoothly, there’s been a light learning curve as I get used to daily driving our metallic brown 2017 SUV of the Year. The GLC300, it seems, drives differently—more efficiently—than many small luxury crossovers and SUVs.
The issue is largely a personal one, but it’s something I’ve grappled with as I go off to test drive other cars for a few weeks at a time and get back into the GLC, and it’s something I suspect many new GLC buyers will deal with as they get used to their new cars.
The issue, I think, is that the GLC is tuned too efficiently.
Hear me out. What happens when you get off the gas when you’re driving your gas-powered car? You probably start noticeably slowing down as you coast. In other words, you’re getting a small but obvious amount of engine braking from your car.
You don’t really get that in the GLC. Get off the gas as you approach a stop light or traffic, and the Mercedes doesn’t seem to naturally slow down—instead it coasts along for about four Mississippi before finally beginning to shed speed. From an engineering perspective, this trait probably is exactly what Mercedes’ engineers intended from the GLC’s 2.0-liter turbo I-4 and nine-speed automatic (not to mention low-rolling resistance tires) as it’s wasting as little kinetic energy as mechanically possible.
It still takes some getting used to, though—especially since it means I’m pressing a lot harder on the brakes than I would otherwise to avoid rear-ending a fellow motorists.
I wanted to test my theory so while I was out of the country on assignment I handed the keys to the GLC off for some fuel economy testing. On the EPA’s fuel economy test, our all-wheel-drive equipped GLC300 is rated at 21/28/24 mpg city/highway/combined. We sought to duplicate the EPA’s results with our very own Emissions Analytics team and netted a Real MPG of 19.2/29.3/22.7. That’s an 8.6 percent dip on the city cycle, 4.6 percent increase on the highway cycle, and an overall drop of 5.4 percent on the combined cycle. Looks like the numbers don’t necessarily back up my theory, but it’s worth noting that our Real MPG tests are all done under a vehicle’s default drive program, which in the GLC300’s case is Comfort mode. We’ll test the GLC again at a later day in Eco mode, which uses tricks such as automatically putting the transmission into neutral while coasting to eke every last mile from each gallon of fuel.
In the meantime, I’ve spent the last few weeks road tripping our Mercedes GLC300 4Matic up and down California, and I think it’s safe to say I’m finally getting used to its unique driving quirks.
More on our long-term Mercedes-Benz GLC300 here:
