The reply from SOA:

The following is information I was able to obtain regarding our efforts to reduce carbon build up on direct injection engines:

Older direct injection systems that experienced carbon build up were so called “lean burn” systems. Unfortunately, these systems suffered many times from uneven combustion due to variations in the fuel and air mixture throughout the combustion chamber. This created a mix of lean and rich conditions resulting in variations in combustion temperature and uneven burning of the gasoline. This uneven burning lead to the condensing of unburned and partially burned hydrocarbons which over time resulted in carbon buildup.

Subaru engineers understood this when they created our current direct injection system. They developed innovative yet simple systems to manage and control the combustion variations inside the combustion chamber. These include features such as specially shaped piston crowns, multi-patterned injection spray, and tumble generator valves. All of which promote the precise swirling and intermix of fuel and air under the variable conditions required across the full range of power requirements.

When combined with very high fuel pressures and extremely short injection duration of the Subaru direct injection system, stoichiometric combustion is maintained across the combustion chamber resulting in very even and complete burning. As a result, abnormal residue and carbon deposits are not created and engine performance and fuel economy are maximized.

 

If you plan to do another lease, don't think it much matters which one you buy.

 

Actually going to keep the next one. It will be my 5th Subaru.

 

Get the 3.6. Let the turbo prove its self over the coming years.

 

The 2019 Touring with the 3.6 will be very comfortable, quick and should be very reliable for you. It is not just the last model year of the 5th generation, it is really the best year, as the 2019 is very different from the 2015 and even your 2017. It is very refined having undergone many improvements and well screwed together. I think it's a good choice.

 

I'd go with the '19 Touring as long as you don't need the extra size of the Ascent. Our 3.6's have been excellent.

 

If you continue to lease, what difference does carbon buildup make? You’re going to flip a car way before any mechanical issues arise unless you plan on clocking 25K miles/year. In that case, leasing isn’t favorable.

 

Since you are looking to buy I would go with thew tried and true EZ36D if I were in your shoes. I likely will be in your shoes in the next few years and will be looking at a 2019 OB as well. The H6 is well suited for the OB platform if you have a full family in it and like to load the rear with cargo, very smooth and has a ton of grunt to pass people or merge easily into fast moving traffic. It isn't bulletproof but it proved very reliable especially if well cared for and has a good track record of doing so.

The new DI turbo engine is my only hang up with the Ascent - if offered with the H6 it would be an easy yes for me. I, like you, don't buy Subaru's statement of how they fixed the carbon build up issues. AFAIK no manufacturer has fully solved the problem except for Toyota but they still use port injection in their D4S system to achieve this. From my understanding the issue isn't in the combustion chamber as much as it is in the intake air having oil in it from the PCV system and it eventually building up on the intake valves from a lack of cleaning from the injection spray.

The real world mileage difference doesn't seem to be large enough to make me want to stray from the H6 to the turbo engine. I'm a fan of right sizing an engine and I would take a less stressed H6 over a higher strung turbo 4 any day. Yes the turbo motor has more torque and slightly more hp, but watch enough detailed car reviews and you will start to understand that NA engines are much more consistent even in heat soak conditions than any turbo is. Savage Geese on YT has many well done car reviews discussing the lack of consistent power with newer small turbo motors.

IMO the 2019 3.6R OB is a good balance of a reliable engine and newer tech that Subaru has started to utilise. I'm not saying that the new turbo motor is a flop, I just think for someone who wants to own an OB for as long as possible, the H6 is a better bet. I personally would never purchase a vehicle with it being the first year of a major change like a new engine.

 

the 2019 will hold a good trade in value for the first few years - so if you get a good enough deal now on what's left (which there are great deals), even with a trade if you "must have" a Gen6 in 1 or 2 or even 3 years, you won't lose too much on the trade (or just sell it).

I got the 2019 to get all the improvements over the earlier Gen5 car, have a new, zero mile H6.... figure if I really want a Gen6, I'll be in a good spot to trade in/sell and get a deal on a Gen6 car... not the first year - get all the improvements over time with the model. 2023 or 2024. Maybe. (the only thing that really is interesting to me about the car is the new global platform, and the seats look very comfortable - not enough to get one the first year for sure).

Get the 2019, save some money. Then just keep it.

 

Thanks for the advise. I think I will keep my 17 and watch the forums for updates on the new engines. The 3.6 inventory is slim now. I waited too long... Either way it has been a great Outback and never had an issue other than a window motor being replaced. I still have my 2011 and it is still going strong