Tuesday, April 9, 2013

Naturally Aspirated Need Not Apply

Here's the thing.

I've spoken before about the crock that is the small displacement, turbo engine. However, my problem doesn't stem from these engines themselves. It comes from the fact that many companies are ignoring better options to follow the trend.

I think the best example of this is Volkswagen's ubiquitous 2.5 inline 5. Next year it is being relieved of duty to make room for a shiny, new, direct injected, 1.8 liter, turbo four. Notice all those adjectives? Well, who's to say that if the 2.5 was given the same advantages that it wouldn't be just as good? Or maybe even better.

However, the problem comes down to consumers. They want a car that scores the magic 40 mpg EPA highway rating, regardless of what they get in real-life driving. Naturally aspirated engines often test better in application, but that doesn't look good in a 30 second television spot.

What's more, they're often faster. They are not dependent on any other system, besides their own natural torque curve. Direct injection only amplifies torque characteristics. An all aluminum, direct injected 2.5 might not hit the 40 miles per gallon on the highway, but it would return 35 while doing 0-60 in 7 seconds.

But that might crimp the style of the GTI and GLI. But won't a 40mpg, 8 second to 60 crimp the style of their diesel offerings? Seems like a DI version of the 2.5 is exactly the difference splitter the lineup needs.

And that, that's the thing.


  1. If we look at the FR-S/BRZ they have direct injection and produce about 200hp/liter at a not too extravagant 7000rpm. If vw cared about their 5 cylinder, they could easily bump the power 50%. At this point in the game however, I don't know if the blame lies with the manufacturer or the consumer. Consumer perception of a smaller engine displacement is that it will get better fuel economy regardless of how much power it puts out.

    So from a marketing perspective, these expensive smaller engines are an easier sell.

    1. From a marketing perspective I can see where they're coming from. I just can't imagine that the poor performance from the small turbos can be good for post-sale opinion. I really can't see why Hyundai got in trouble for inflating numbers when the other companies are doing the same. I guess it just seems more believeable with this new "cutting edge" turbo technology.

      Ps. I woulda liked to seen a high output version of the 2.5 be the GTI engine. Something akin to the old VR6.