Q: Automobile manufacturers, in order to save weight, seem to be favoring 4-cylinder engines over 6- and 8-cylinder versions. How will these 4-cylinder engines, especially those powering larger vehicles, stand up over the long haul compared to larger 6- and 8-cylinder models?
_Fred Ford, Walnut Creek, Calif.
A: You can count me among the folks asking themselves the same question. Because on a long-term basis, the jury is still out.
Smaller, high-output turbocharged engines are certainly more complicated and are subjected to greater stress than larger, non-boosted engines. But thanks to amazing metallurgy, sophisticated design methods and testing, and smart engine management, the durability seems to be on par.
The things that would go through my head if flipping a coin between let's say Ford's techy 2.7-liter turbo V-6 engine and a new-generation 5.0-liter V-8 naturally aspirated engine would be:
What's the real-world difference in fuel economy?
Will premium fuel be needed for the 2.7-liter for the type of driving I do most?
Is there enough of a difference in fuel dollars saved to justify the repair costs down the road of a more complicated, harder-working engine?
That said, you should also consider that the V-8 mentioned above _ an all-aluminum DOHC _ is also bristling with efficiency-enhancing technology such as variable valve timing, intake port tuning, and direct fuel injection, resulting in it costing $1,000 more up front. These features have proven pretty reliable but also add cost to any needed repairs.
For a light-duty pickup, it's a toss-up for me. If it's bleeding-edge technology, why not lease and hand the vehicle back before the warranty is over? That's what I'm doing with my Chevy Volt. It has so many freaky glitches that I'm thankful I won't be stuck with it out-of-warranty. And that's not even taking into consideration how the ultra-complicated powertrain will perform long-term.
For a heavy hauling truck you're wanting to purchase, my choice would be the 5.0-liter V-8 engine. And I'd give it the very best in maintenance throughout its life. An aluminum engine requires scrupulous cooling system maintenance, and the variable valve timing system really needs clean oil.
When I was a kid, my mom had a Ford Galaxie with a 390 V-8 cast iron engine. One day, the little hose between the water pump and intake manifold split wide open, spewing coolant. The engine became so hot it seized up before the idiot light for over-temperature ever illuminated! After the engine cooled down, I replaced the hose. Low and behold, the engine started right up, ran great, and lasted another 100,000 miles without a hitch. Try that with a newer engine and you might as well throw the car away!
