Truck Engines! V6 Turbo or V8?
There's a common conversation today around truck engines and whether a V6 turbo is better/worse/comparable to a traditional V8. There's fans on both sides of the argument, and I am decidedly on the side of the V8, but let's look at this a little objectively and see what's what. (Also, I'm going to stick with Fords, only because that's what I've got experience with.) Straight from the Ford media center (a.k.a. - official marketing stats) we see that the 2014 F150 with a 5.0L V8 has 360 HP and 380 ft/lbs of torque with fuel stats of 15 mpg city and 21 highway. Meanwhile, the 2015 F150 with a 3.5L turbo V6 has 365 HP and 420 ft/lbs while getting 17 and 23 mpg respectively (4x4). Transmissions have the same gear ratios for both trucks, that's out of the equation, and final drive ratios have a couple options, which we know will affect things, but both trucks we're discussing have a final drive of 3.55:1.
So here's the argument from the V6 side: "It has more power and more torque, so it's obviously better."
And from the V8 side: "It's a V8 with no power adder, so the power is more readily available/consistent."
In the real world, we're concerned with a few things: capability - obviously - and efficiency, because we all don't have bottomless pockets. That's the frame for our considerations.
Now then, regular, day-to-day commuting, the V6 outshines the V8, with more than enough power from both engines, and the V6 achieving 18.5-20 mpg and the V8 seeing more in the range of 16.4-18.5, with a fairly easily achievable 17.3. What's that save you per year of commuting? $200 (assuming 12,ooo miles per year and $3/gallon fuel and an average mpg difference of 2; actual results may vary).
How about towing and hauling? We all know that most trucks these days aren't used for anything more than hauling kids around town, and the occasional couch for a friend, but what about the exception to the rule? What about the guy the truck was designed for? For him, the difference can be significant. Towing with the V6 can result in numbers as low as 7 mpg at 70-75mph. That's reminiscent of trucks without overdrive! Meanwhile, our V8 counterpart consistently realizes 12-13.4 mpg under the same circumstances. That's as much as a $2300 difference in favor of the V8!
Why you ask? Simple - in order to achieve the power output of the V6, you have to add fuel, and lots of it; significantly more than you have to supply to the V8 under load. Power-adders are great, and they've been used on the track for years, but at a cost.
So what does this mean? Eh, not much really. There's a place for each engine, it just depends on your needs. All powertrains have pros and cons, from electric vehicles with range problems to semi-trucks that get 2 mpg but can travel over a thousand miles between stops while hauling. My advice is get the one that does what you need it to do. Me? V8 all day.