Break in question

I don't think there's concern for damage to an engine by running a fresh motor above 4000 rpm, the danger is if a turbo comes apart at high rpms. If a failure was to happen, better to happen at lower rpm to prevent collateral damage. I suspect the turbo is spinning at over 200,000 rpm by the time the motor is turning 5000 rpm.
Since your motor didn't grenade, you didn't cause any damage.

SkiPro3 said:

I don't think there's concern for damage to an engine by running a fresh motor above 4000 rpm, the danger is if a turbo comes apart at high rpms. If a failure was to happen, better to happen at lower rpm to prevent collateral damage. I suspect the turbo is spinning at over 200,000 rpm by the time the motor is turning 5000 rpm.
Since your motor didn't grenade, you didn't cause any damage.

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Subaru’s sub-4,000rpm / vary engine speed for the first 1,000mi mandate has nothing to do with turbos or blowing turbos up. You can easily spin a turbo‘s impeller at max speed well below 4,000rpm.
Impeller speed has to do with load, not engine rpm.

This recommendation from Subaru has been the exact same on every new Subaru I’ve bought since the 90’s (a bunch), naturally aspirated or turbo charged.

You’ll be fine with those brief moments of 5k rpm OP. As far as varying engine speed on a lonely highway, that’s a little tougher. My first new Subaru I bought I picked up about 500mi away at a dealer and I think I just gently surged the motor raising and lowering rpms every few minutes most of the way home.
No issues up to 40kmi or so when I sold it. Pulled nice and hard as it continued to break in over those miles.

Brake-in angst. There are a lot of strongly held opinions on the correct way to break in a vehicle. Some will say baby it beyond the mfgr's recs, some will say adhere religiously to those recs, some will say break it in like you intend to drive it, and some will say to give it full throttle to max RPM periodically to ensure it "seals". Among racers, the usual is to take a new or rebuilt engine or transmission on a few quick laps or runs to ensure it's OK then run it in races.

Anyway, your few excursions over 4k are pretty mild compared to what some adhere to, and are nothing at all to worry about. Heck, some might argue it's better that you have done that.

Merope said:

Brake-in angst. There are a lot of strongly held opinions on the correct way to break in a vehicle. Some will say baby it beyond the mfgr's recs, some will say adhere religiously to those recs, some will say break it in like you intend to drive it, and some will say to give it full throttle to max RPM periodically to ensure it "seals". Among racers, the usual is to take a new or rebuilt engine or transmission on a few quick laps or runs to ensure it's OK then run it in races.

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Race build engines are sterner stuff. Anyways, every Ascent was dyno tested at the factory for the initial testing and break in. That too is taken into account in the break in procedures Subaru puts in their manuals. So, the "full throttle..." etc break in suggestions were already performed for initial seal and ring set, and is expected to be followed by the more sedate customer break in listed in the manual.

Side note: It was really neat watching them drive Outbacks and Ascents onto the dynos and testing them. Car hits the final assembly point, the last bit of work gets done, and it does a U-turn off the line, to one of the dyno stations. Drives on, gets locked into place, and the test begins. Unlocks, and drives off for the outdoor stuff and a trip to the "port" for accessories.

Robert.Mauro said:

Race build engines are sterner stuff. Anyways, every Ascent was dyno tested at the factory for the initial testing and break in. That too is taken into account in the break in procedures Subaru puts in their manuals. So, the "full throttle..." etc break in suggestions were already performed for initial seal and ring set, and is expected to be followed by the more sedate customer break in listed in the manual.

Side note: It was really neat watching them drive Outbacks and Ascents onto the dynos and testing them. Car hits the final assembly point, the last bit of work gets done, and it does a U-turn off the line, to one of the dyno stations. Drives on, gets locked into place, and the test begins. Unlocks, and drives off for the outdoor stuff and a trip to the "port" for accessories.

Click to expand...

I need to drive to Indiana and take a tour!! Sounds cool.

To the OP, you have one more vote for don’t worry about it.

To the sidebar, The plant tour was really cool, especially to an engineer like me.

I've never been to a Subi plant but got a VIP tour of the Nummi plant in Fremont CA (joint venture between GM and Toyota) before it became the Tesla plant.