1968-1975 BMW 3.0 CS / CSi (E9) — MPG & Fuel Facts NO OFFICIAL EPA RATING

The EPA's public fuel-economy dataset only goes back to 1984 — the 1968-1975 BMW 3.0 CS / CSi (E9 coupe) predates it, so there is no government-rated MPG number for this car anywhere, including here.

Estimated 14–19 MPG combined.

Period tests of the E9 coupe cluster around 14-19 US mpg — Road & Track measured 19 mpg in the 2800 CS, Motor Sport saw about 17.5 US mpg (21 Imperial) in a 3.0 CS, and owner reports run to the low teens in hard or city driving.

This is our estimate, not an EPA rating — built from the period road tests, marque-specialist guides and corroborated owner reports cited below, hedged where sources vary. Treat it as a ballpark for planning, not a spec to rely on.

The E9 coupe began as the 2800 CS (2.8-liter M30 carbureted six, 1968-71), then became the 3.0 CS (twin Zenith carbs, ~180 hp DIN) and 3.0 CSi (Bosch D-Jetronic injection, ~200 hp) from 1971; the US only officially received carbureted cars, through 1974. Transmissions were a 4-speed manual or 3-speed automatic.

Road & Track's February 1970 road test data panel lists 'Fuel consumption, normal driving: 19 mpg; cruising range 350 mi' on the 18.5-US-gallon tank for the 2800 CS. Motor Sport (October 1971) reported 'fuel consumption is around 21 m.p.g.' for the 3.0 CS — Imperial gallons, about 17.5 US mpg.

Owner discussion on the E9 registry forum puts a carbureted 1973 3.0 CS in daily mixed/city use around 14 US mpg. As indirect EPA context, the 1976 EPA guide rates the mechanically related 3.0Si sedan (same M30 3.0 six, injected, US emissions) at 17 mpg combined. The injected CSi runs slightly more efficient at cruise, but no separately measured CSi test met the sourcing bar, so none is quoted.

Sourcing note: Two independent period-measured figures, but only one is for the 3.0-liter car, and the CSi specifically has no dedicated measured test in hand.

Sources: Motor Sport Magazine archive — 'Road impressions: BMW 3.0 CS' (Oct 1971, quote verified) · e9coupe.com — full 6-page scan of Road & Track Feb 1970 BMW 2800 CS test (data panel read from scan) · e9coupe.com — 'E9 coupe good for daily driver?' owner mpg reports · EPA 1976 Gas Mileage Guide (BMW 3.0Si row, engine-family context)

All classics Search BMW 3.0 CS / CSi (E9 coupe) on FuelFacts (in case a later model year is in our 1984+ EPA data)