Of Engines and Things
I'm not trying to be a downer, but from the copious amounts of research I've put into this, I wanted people to understand why asking for the H6 in the Ascent is a step backwards that won't happen.
Well, there's a whole lot of misconceptions about the available and desired engine options, as well as about the competition. I think one of Subaru's most difficult things is to portray what is in the Ascent in short form, yet also portray why they think it's best for what it is intended to do. I'm going to go into my standard ridiculously long form.
So, let's start with what we got - the FA24DIT.
We got an "all new" FA24DIT and new high torque CVT. But that's not really the full story. Our FA24 is based off the FA20 that's been successfully used for over half a decade. The direct injection method has been used on FA engines for over half a decade. The FA series is based on the FB series, which is a little older. The FA20F Direct Injection twin scroll turbo Subaru boxer engine was released in 2012.
So, we don't have anything groundbreakingly new. The FA24 has been revised with stronger internals, a little more space, different compression and some other tweaks for handling the higher torque and heavier loads (compared to the FA20), and Honeywell designed a "brand new" MGT-22 turbo for the Ascent. Honeywell. It's based off their tried and tested previous designs, just as the FA24 is based off the FA20 and FB series before it.
Short version is, we already have an idea of what to expect out of our FA24's, because
DIT FA's have been out and about for years - over half a decade of active use.
Let's touch upon the 3.6L H6.
It will absolutely positively not, in its current form, be suited to moving the Ascent. The thing puts out less power and less torque and doesn't have as flat of a torque curve. And it gets faaaar worse.
The thing gets the same gas mileage on a car a thousand pounds lighter than the Ascent. Think about that. Adding 150 pounds and a little more rolling resistance with bigger rims drops the Ascent a mile per gallon. So, stick the H6 in a car a thousand pounds heavier than the Outbacks it's designed for, and you're talking about dropping the gas mileage into oblivion. Don't believe me? Anyone who's got an Outback 3.6R, feel free to load an extra thousand pounds into it, plus yourself, and run through a couple tanks of gas.
Let's touch on what it takes to make the H6 engine perform well enough to move the Ascent.
- Engine on/off at lights: that helps with gas mileage, but not enough.
You still don't have enough power in the current H6.
- Cylinder shut off: sure, this actually works with gas mileage - and manufacturers are now learning that it's at the cost of reliability.
You still don't have enough power in the current H6.
- Turbo: now you've got the power, but are still far away from the gas mileage requirements (eg: look at the Ford Ecoboost 3.5L TT in the Expedition: 17 mpg in the city and 24 mpg on the highway). This is the only way you get enough power (and then some) on the 3.6L H6 - other than designing a new and bigger non-turbo engine.
If you add one pound to the Ascent's GVWR, and a full frame, then, sure,
market it as a light truck and make a powerful 6 with a turbo for it.
This isn't a light truck. Nor is that the market Subaru needed to go after. It would be another niche item, like the manual in the Outback. Fact is, that disappeared for more than fuel economy reasons. For instance, there were 881 manuals produced in a model year that had roughly 100,000 Outbacks and Legacies built. That's literally less than a percent.
So, making a brand new 6 cylinder that performs maybe as well as the new 2.4DIT for the 400 people who may want it would be a bad move, in my opinion. Regardless, it would be a big challenge to make something efficient that would move the Ascent at all. Look at what the competitor V6's do.
In Summary:
- You may think you want it, but, no, you do NOT want the less powerful, peaky torque curve, less efficient 3.6L H6 in the Ascent. The Ascent would be staggeringly slower and much much less fuel efficient.
FYI: the performance numbers I've been citing over the last couple months have not been Subaru's. They've been Motor Trend's.
The Ascent matches the performance of the MUCH lighter H6 power Outback at the same gas mileage.
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- The Ascent will absolutely not make mpg requirements for the class with a 6 cylinder, turbo or not, except perhaps with both engine shut-off and cylinder shut-off being used, which increase complexity, cost and problems.
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- Other than luxury car manufacturers, very few, if any, cater to a market segment of less than a percent... and that's likely (like with the manual) how many people would want worse gas mileage with (a) far worse performance of the H6, or (b) an H6 turbo that's got even worse gas mileage but better performance. Not a good business move.
If Subaru makes a light truck one day, then things may be different.
