2013 Acura RDX highlights myth that turbo engines are more fuel efficient

The 2013 Acura RDX has proven to be an excellent test case to prove or disprove manufacturers’ claims that small turbocharged engines deliver the same power and better fuel economy. Many manufactures even go further saying that the turbocharged small engine delivers a better driving experience than the larger, normal aspirated engines from the same line of cars. It is easy to assume this is all true, but is it? Let’s take a look at this model closely and pick one other for comparison to see if the turbo engine is really more efficient and if customers prefer its driving dynamics.

A few years back when Acura introduced the RDX it highlighted two main things; the Super Handling All Wheel Drive system and the new turbo 4-cylinder engine. This was a new path for Honda/Acura, who had always been a normally aspirated engine company in the US until this point in time. This was about the same time that Acura had just about completed killing off its best-selling car model the Integra, which was later rebadged and restyled. Acura chose to abandon this premium pocket rocked market to pursue clients that had a little more education, years lived, and better zip codes on their addresses. Acura thought that the new engine might be well received by its upscale targeted cliental. When the vehicle was driven by customers and the motor press the overall impression was positive. Sales were never tremendous, but it was not a flop. Now Acura has introduced almost exactly the same body style, but with a totally different personality.

Let’s look at the Spec. sheet of the 2013 Acura RDX and the prior model. The old turbo engine (which was supposed to be state of the art just a few years earlier) had 240 HP and the 2WD version had EPA rated fuel economy of 19 city/ 24 highway. The new 6-cylinder engine, which is basically the same engine Acura has been using in other Honda and Acura models all along, now has an EPA rating in the same car of 20 City / 28 highway. So in other words the new engine has dramatically better fuel economy and it is a 6 cylinder non-turbo. Oh, and it has 273 HP, about 14% more power and 15% better highway mileage. Other things changed on the Acura including the transmission, so the comparison only goes so far. However, the transmission is not revolutionary and could have been used all along.

With regard to driving dynamics, let’s let the customers speak. Even though Acura dropped the high-tech all-wheel drive system and kept the body almost identical, the new RDX has jumped up in sales 142% according to an Acura press release this week. Perhaps the turbo lag was an issue? Perhaps customers prefer smoother V6 engines with more power and better fuel economy?

In order to give this story some balance let’s take a second example, the Toyota Rav-4, which is a similar vehicle to the RDX in terms of size and shape. Toyota has long offered the vehicle in both V6 and 4-cylinder (non-turbo versions). Mid-cycle, Toyota implanted its newest 4 cylinder engine that has its latest fuel savings technology. The V6 is basically unchanged. In that vehicle the standard 4-cylinder has mileage ratings of 22/28 mpg. The V6 has ratings of 19/27 mpg. However, although the 4-cylinder is slightly better in terms of fuel use the driving experience is dramatically different. The V6 RAV-4 has long been one of Toyota’s fastest vehicles. The 4 cylinder is not considered quick by any means.

Looking closely at the turbo vs. normally aspirated engine debate yields some surprising facts. The 2013 Acura RDX provides an excellent comparison of which drivers choose given the option.