4BA-BT5
Subaru Legacy BT5 specs
BT5 is the model code of the Subaru Legacy. Japan’s transport ministry lists it in its fuel economy lists from 2023–2026 under the model type 4BA-BT5. A genuine car’s chassis number starts BT5-.
BT5 at a glance
- Make
- Subaru
- Model
- Legacy
- Model code
- BT5
- Model types
- 4BA-BT5
- In MLIT’s lists
- 2023–2026
- Engines
- CB18 1,795 cc petrol
- Gearboxes
- CVT automatic
- Drive
- four-wheel drive
- Kerb weight
- 1,680–1,720 kg
- Official fuel economy
- 13–15.8 km/L (37–45 mpg)
Fuel economy is from Japan’s official tests and is usually better than you’ll see on UK roads. MLIT doesn’t list power or torque.
4BA-BT5
Listed 2023–2026. The 4BA prefix (our explanation, not MLIT’s) means petrol passenger car certified to Japan’s 2018 emissions rules, 25% below their limits. Check 4BA-BT5 against ULEZ and clean air zones.
| Engine | Gearbox | Drive | Weight | Seats | Fuel economy | Listed |
|---|---|---|---|---|---|---|
| CB181,795 cc petrol | CVT automatic | four-wheel drive | 1,680–1,720 kg | 5 | 15.8 km/L45 mpg, Japanese JC08 test | 2023–2026 |
| CB181,795 cc petrol | CVT automatic | four-wheel drive | 1,680–1,720 kg | 5 | 13 km/L37 mpg, WLTC test | 2023–2026 |
Each row is one version as MLIT lists it. A version can appear twice when MLIT gave figures on two tests that year. Low-emission stars and trim names aren’t shown. MLIT gives fuel economy in km/L; the mpg figures are our conversion to UK gallons. Japanese tests are gentler than real UK driving, so expect less.
BT5 build year by chassis number
Japan’s carmakers list the chassis numbers each code was built with every year from 2015. Find the serial below, or use the build year finder.
| Built | Chassis numbers |
|---|---|
| 2021 | BT5-002013 to 004135BT5-004137 to 004140BT5-004142 to 004143 |
| 2022 | BT5-004136 to 004136BT5-004141 to 004141BT5-004144 to 006766BT5-007227 to 012556BT5-016003 to 018145 |
| 2023 | BT5-018146 to 021931BT5-024002 to 026365BT5-026368 to 026368 |
| 2024 | BT5-026366 to 026367BT5-026369 to 030428BT5-037001 to 039255BT5-039257 to 039259BT5-039261 to 039261 |
| 2025 | BT5-039256 to 039256BT5-039260 to 039260BT5-039262 to 045236 |
From the JAMA chassis number lists: 車台番号一覧表. We keep only the chassis code, serial ranges and year. JAMA calls them reference information, not a certificate.
Check a BT5 before you buy
Make sure the car is what the advert says: the chassis number on the V5C should start BT5-, and the engine and gearbox should match one of the versions above. Our free check reads the UK MOT history and compares it with the chassis code.
Other Subaru Legacy model codes
Questions
What engine does the BT5 have?
MLIT lists the Subaru Legacy BT5 with CB18 1,795 cc petrol.
What fuel economy does the BT5 get?
Officially between 13 and 15.8 km/L (about 37–45 mpg), depending on the version, on Japan’s own tests. Real-world figures are usually lower, especially against the older 10-15 mode test.
How heavy is the BT5?
Between 1,680 and 1,720 kg kerb weight, depending on the version.
Is 4BA-BT5 the same as BT5?
Yes. 4BA-BT5 is the full model type: the letters before the hyphen are Japan’s emissions code, which changed as the rules were tightened, and BT5 is the model code. The chassis number starts with BT5-.
About these figures
The model types, engine codes, capacities, gearboxes, drive, weights, seats and km/L figures are copied from MLIT’s yearly lists of cars on sale in Japan each March, so “listed” years are list years, not exact production dates. The English model names, mpg conversions, emissions code explanations and chassis number matching are ours. Lists before 2013 were printed as PDFs that we read by machine; where an older list gives an engine code that doesn’t match its capacity, we’ve used the figure the same model type has in other years. Check anything that matters against the car’s own papers. Spotted a mistake? Email [email protected]. All Subaru model codes.
Source: Ministry of Land, Infrastructure, Transport and Tourism (MLIT), Japan, fuel economy lists 2004–2026, used under the Public Data License 1.0. Edited and translated by JDM History.