People search for "kei truck mpg" wanting one number. The honest answer is that no such number officially exists, and that the question behind the question — is this thing cheap to run? — has a much better answer than the mpg figure alone would give you.
There is no EPA rating, and that is not a dodge
EPA fuel economy ratings exist for vehicles certified for sale new in the United States. No kei truck was. They arrive here as 25-year-old imports under the federal exemption, which means no manufacturer ever put one through an EPA cycle and there is no entry for any of them on fueleconomy.gov.
So every mpg figure you find online for a kei truck comes from one of two places: a Japanese manufacturer test cycle, or somebody's trip computer. Both are worth something. Neither is an EPA rating, and anyone presenting one as if it were is guessing at you.
The Japanese figures are the more useful of the two. Manufacturers published economy on the 10-15 mode cycle, and later the JC08 cycle, and for 660cc kei trucks those results generally landed in a band that works out to roughly 35 to 45 US mpg. Read that as a laboratory ceiling rather than a forecast — the Japanese cycles were gentler than the EPA's, and the trucks were tested empty, new, and on flat ground.
We have not instrumented a truck and we do not publish a measured mpg figure. The figures above are published manufacturer and class data for the engine families, not our own test results.
What the mechanical picture suggests
You can reason toward a sensible expectation without making up a number. A kei truck is somewhere around 1,500 to 1,800 lb empty depending on model and drivetrain, carries a naturally aspirated 660cc three-cylinder — four, in the Subaru Sambar — and makes something in the region of 40 horsepower.
That combination produces an economy curve shaped the opposite way round from a modern car's. Light weight and a tiny engine are enormously efficient at low speed. But the cab is a brick, the gearing is short so the truck will pull away with a load in the bed, and there is no meaningful power reserve. Push one to 60 mph and the engine is working near the top of its range against bad aerodynamics, which is exactly where small engines stop being frugal.
Practically: a kei truck doing what it was designed to do — 25 to 45 mph around a property, a farm, a site or a campus — is very cheap to feed. The same truck used as a commuter at sustained highway speed is merely ordinary, and it is unpleasant for other reasons we have written about separately.
What is actually on our lot, and why it changes your number
Here is where we can stop reasoning and start counting. Across the 743 trucks currently listed in our kei truck, mini dump truck and kei 4x4 categories, this is the specification mix:
| Specification | Count | Why it matters for fuel |
|---|---|---|
| Manual transmission | 673 of 743 | The efficient default on a vehicle with this little power |
| Automatic or CVT | 69 of 743 | Easier to drive; a torque converter costs you something |
| Four-wheel drive | 465 | Transfer case, front diff and second driveshaft all cost fuel |
| Two-wheel drive | 100 | The most economical configuration you can buy here |
| Median recorded odometer | 52,455 miles | Engine condition moves economy more than any option does |
| Median model year | 1998 | Mostly fuel-injected, pre-emissions-plumbing simplicity |
Counts are of vehicles listed as available at the time of writing. Drivetrain is recorded on 574 of the 743 — the 465 and 100 above are counts within those records, not within the whole fleet, and the remaining nine are RWD or FWD. Odometer is recorded on 703. Those readings are what the vehicle showed when it was listed; we report them, we do not warrant them as lifetime mileage.
Two of those rows do most of the work. The fleet is overwhelmingly manual — nine in ten — and where we have the drivetrain recorded, four in five are four-wheel drive. Four-wheel drive is the single biggest fuel penalty on offer, and it is also the thing most buyers are specifically looking for, because it is what makes the truck useful on soft ground. If economy genuinely is your priority and your ground is firm, the 2WD trucks are the cheaper vehicle in both directions: less to buy and less to feed.
Condition matters more than any of it. A tired engine with worn plugs, a stretched timing belt and a sticking choke will lose you more mpg than the transfer case ever will. Across the fleet, 331 of the 703 trucks with a recorded reading are under 50,000 miles and 25 are over 100,000, so there is real spread to choose from.
Fuel is the smallest line in the budget
This is the part the mpg question tends to miss. If you drive 3,000 miles a year of property work at something in the 30s, your annual fuel bill is small enough that a five-mpg difference between two trucks is not what you should be deciding on. The costs that actually add up are these.
What you pay to get one. Live prices from current stock:
| Category | Priced in stock | Lowest | Highest |
|---|---|---|---|
| Kei Trucks | 426 | $3,920 | $28,250 |
| Mini Dump Trucks | 71 | $4,995 | $30,500 |
| JDM Vans | 46 | $4,090 | $19,995 |
| Kei Vans | 45 | $4,977 | $30,500 |
| JDM Sedans & Sports | 25 | $7,795 | $39,995 |
| Other JDM Imports | 17 | $4,180 | $38,995 |
| Kei 4x4 & Jimny | 10 | $4,977 | $10,995 |
| Kei Cars | 9 | $6,700 | $12,995 |
There are 949 vehicles on the lot in total. The cost guide breaks down what moves a kei truck's price.
Servicing. Cheap in parts, occasionally awkward in labour. Oil, filters, plugs, belts and brake friction for these engines are ordinary consumables and widely available. What catches people out is finding a shop that will take the work — plenty of independents are perfectly capable and simply have not seen one before — and sourcing model-specific body, trim and electrical parts, which often means ordering from Japan and waiting a few weeks. The bill is rarely the problem; the lead time sometimes is.
Tyres. Almost every kei truck runs 12-inch wheels, typically in a light-truck size. They are cheap, because they are small. They are also not something every tyre shop has on the shelf, so order ahead rather than turning up.
Registration and insurance. Entirely dependent on your state, and in some states not available at all. This is worth settling before you think about fuel, not after.
Where the economy really comes from
The reason these trucks make financial sense is not the mpg figure. It is that the whole vehicle is cheap: cheap to buy, cheap to insure where you can insure it, cheap to feed, cheap to tyre, and small enough to drive and park where a full-size truck cannot go at all. Set one against keeping a half-ton pickup to move mulch around a property twice a week and the comparison stops being close — not because of fuel, but because of everything.
What it is not is a cheap commuter car. If the plan is a 40-mile highway round trip five days a week, the fuel savings are not the issue; the vehicle is.
Before you buy one for the fuel bill
Importing a 25-year-old kei truck is legal in every state. Registering one for road use is not — that is decided state by state, and several refuse it outright, including New York, where we are based. If your plan involves public roads, settle that question first with our state-by-state guide and your own DMV, because no fuel figure matters if the truck cannot be plated.
If you want help picking the most economical configuration for the work you actually do, tell us the ground and the mileage and we will point you at the right trucks. Get in touch, browse the kei truck inventory, or read the model comparison if you are still choosing a platform. Every vehicle we sell includes free insured door-to-door delivery anywhere in the continental USA.