SpaceX Founder says Raptor 4 engine will be 10 times better than Merlin

SpaceX Founder and CEO, Elon Musk, said that the Raptor 4 engine will be more powerful and efficient than the current generation of Merlin engine used in Falcon 9.

He said that the upcoming Raptor 3 engine will be 2 to 4 times better than Merlin in per-ton cost of thrust, and it will exceed Merlin in thrust-to-weight ratio. This metric measures engine production cost divided by thrust output (in metric tons-force).

Merlin’s current baseline is ~$2,900/ton (such as $250k engine/86 tons thrust). Raptor 3, with a new and improved design targeting $700–$1,500/ton (such as ~$200k–$420k/280+ tons), representing 2–4× improvement over Merlin in cost per ton of thrust.”. This makes the new engine 2 to 4 times cheaper due to an efficient parts assembly, higher chamber pressure, and better component printing.

SpaceX is preparing the Raptor 3 assembly for Starship V3 and the next-gen Super Heavy booster. Its design removes the heat shield requirement on the Super Heavy. A single Raptor 3 produces 280 tf of thrust compared to 230tf on the predecessor. Each of the Raptor 3 saves more than 1 ton of vehicle mass, allowing the company to increase the upper stage’s payload capacity by 40 tons compared to Starship V1 and V2.

Raptor 4

Musk also mentioned that Raptor 4 will be 10 times better than Merlin, which will focus on extreme simplification for more efficiency in operational cost. Once achieved, this milestone will allow SpaceX to operate the Starship fleet at a very low cost for Moon and Mars missions.

SpaceX Founder and CEO, Elon Musk, predicts the Raptor 4 engine’s cost per ton

Currently, the SpaceX founder has not shared plans for Raptor 4 integration, but it’s likely to launch somewhere in the next year or early 2027 with a new Starship launch.