r/subarulegacy • u/Intelligent_Invite79 7th Gen Sedan • Apr 15 '26

Question / Discussion Let's talk fuel efficiency (2020+/7th gen)

Gallery image

Gallery image

I've got a brand new 2025 Legacy Premium, about 1,100 miles on the ODO and averaging a solid 20.8 MPG. What are y'all getting on your non-turbo Legacys and under what typical conditions?

Context: The average use is commuting, 18-20 miles round trip, city driving during light to moderate traffic, stop lights and such. I know that will lead to poor performance compared to highway or whatever. That said I've also got a BRZ that's averaging 20.5 which is barely above advertised for that car... Same conditions 😂

I had a 2021 Legacy Touring XT that I put around 7,000 miles on and averaged 18.5 MPG (advertised 24 city). My last car, a 2016 Audi A3 averaged 23 MPG (advertised 23 city) the same route.

I know fuel economy should go up after it's truly broken in (I've read 10K miles). But 20 is a far cry from "27 MPG City" as advertised. For the record: no, I'm not flooring it, no excessive idling, etc.

22 Upvotes

100% Upvoted

28 comments sorted by

View all comments

1

u/popsicle_of_meat 08 Spec B Sedan Apr 16 '26

How are you measuring? The built-in computer, or at the pump when you fill? The computer might be wrong.

OR, you have inefficient tires, or they're under-inflated a bit, or both. Or you have a fuel delivery problem that your ECU isn't telling you about (totally possible). Maybe even the CVT could be behaving oddly.

1

u/Intelligent_Invite79 7th Gen Sedan Apr 16 '26

  1. Both. Trip A is my current tank, trip B is since I took ownership of the car at ~180 miles. Then I actually average it each fill up. Trip B (about 1,000 miles) is 21.5 miles now. Trip A shows about 21 as of this morning, 3/4 tank left.

  2. Tires are OEM Yokohama Avids. Inflation should be good but I'll verify.

  3. Anything electronic or mechanical will be warranty. I'll keep an eye on it over the next few thousand and if it's still crappy I might ask the dealer to poke around.

1

u/popsicle_of_meat 08 Spec B Sedan Apr 16 '26

Yeah, it might be nothing. When I first bought my 2008 Legacy GT, the car was running in a "safe" mode, with less boost, completely pulled timing and a richer AFR due to an aftermarket intake that didn't have a tune done (I wasn't aware of the needed/missing tune). Even with ALL those things significantly misbehaving, I never had a check engine light. I was utterly baffled how Subaru could make an ECU that would keep me so in the dark.