Sunday, February 22, 2009

The right engine makes all the difference.

Gas mileage in a vehicle has a lot to do with how you drive it, but more importantly is how well matched the engine is to the weight of the vehicle.
I recently test-drove a Mazda CX7. The mpg figures are in the same ballpark as my current vehicle - the Honda Element - averaging about 19mpg. But the performance difference is staggering. The CX7 has a smaller engine but it's turbocharged and that makes all the difference in the world. It's not sluggish. It doesn't bog down going up long inclines, and it just feels altogether more peppy. Well - with a turbo, it would, but the 6-speed automatic gearbox helps too.

So I figured it was the turbo and the lighter vehicle that made it more zippy to drive (I can't bring myself to use Mazda's "Z" word). Well - not so much. The quoted kerb weight for an Element is 3640lbs for the 4WD AT. For the CX7 it's 3930lbs - about 300lbs heavier.

So a smaller (albeit turbocharged engine) in a 300lb heavier car, with 6 gears instead of 4 and returning about the same gas mileage, makes it an infinitely more driveable SUV than the Element.

And this is the problem with the Element overall. It's a wonderful vehicle - totally practical and fun to drive, but it's just out of breath all the time. The engine just isn't up to the job because it's a normally aspirated 2.4 engine from the Civic and Accord. What Mazda did was realise they were hauling a heavier vehicle around and adjust the engine accordingly. Honda didn't. The difference is like night and day.

1 comment:

Dio said...

Chris, I don't think that Honda failed to realize the element's engine is a bit to undersized for the vehicle - I think the real reason the element is equipped with that engine is it's the most marketable configuration Honda could produce given their options - Current Honda production models come equipped one of two types of engines (well, except for the soon to be re-released insight...that kinda has it's own deal going on....but I digress)...: all 4 cylinder engines (despite the displacement) are K series engines and all the 6 cylinder engines are J series engines. Now, considering that Honda, (with one very recent exception) refuses to use turbos on their vehicles, you Element is as peppy as they could possibly make it without doing one of the following (which would greatly increase the production cost) 1) Putting a V6 into the element or 2) implementing a full-blown DOHC cam setup like my RSX Type-S has.... but since the Element is an SUV and that DOHC setup reaches peak horsepower at about 7000 rpm (or 9000 rpm in the case of the S2000's 2.4L 4 cylinder engine... which I think is still the record holder for producing more power per a unit of displacement than any other naturally aspirated engine ever produced) that would have been kinda pointless and silly.

As far as I know, the Acura RDX is the only automobile Honda has ever made with a turbo....and I don't really think there's anything wrong with that per se, as long as a prospective Honda customer really understands what their getting. My problem with forced induction in general is it causes a crapload of extra on an engine. Now in certain contexts, that's not really a problem - like a diesel engine for example... most Diesel engines are built like a tank due to the crazy compression ratios they run at.... throwing a turbo or supercharger into the mix isn't really going to introduce a significant amount of excess wear or reduced reliability in a system that robust. In the context of an unleaded engine however.... forced induction can be problematic and ultimately, it will reduce the overall lifespan one could expect out of any moderately priced (think sub 50000) vehicle (well there are a few exceptions that come to the BMW 135i since it's turbos don't really push all that much boost) Honda knows this, and instead of selling a 4-banger pushing 30-some-odd pounds of boost that will inevitably eat it's own ass (like the mozdaspeed 3) they instead engineer as much reliable performance as they possibly can out of a naturally aspirated engine (which is quite evident in S2000 record I pointed out earlier) going back to that prospective Honda customer, they need to realize their buying a vehicle that (for the most part) puts reliability, engineering and efficiency before performance. Case in point: despite it's "type-s" designation, my RSX isn't particularly fast - it'll do 0-60 in about 6.5 seconds....which is pathetic compared to a Lancer Evo or the Mazdaspeed 3....and is downright shameful in comparison to the BMW 135i's 0-60 of 4.9 seconds............... but when I bought it, I wasn't looking to buy the fastest car I could afford (i suppose if had been...[although I hate to say it] I would have bought a GTO...I know, they're ugly....they're gas-guzzlers...etc. but they are fast and they are dirt cheap compared to anything else that can keep pace with it) No, I bought the RSX because it's 8000 rpm redline, it's 6 speed manual and it's sharp cornering make it blast drive but it's 31 mpg on the highway and freakish cargo capacity (when you fold down the rear seats) make it practical....that's why you buy a Honda - practicality, not performance.