We should hope so! The Merlins have been operational for more than a decade, and the Raptors are still in development. Kerosene has been boosting payloads to orbit for two-thirds of a century, and methane has been doing so for only a couple of years. Harsher or not, we should know how to fly with kerosene, by now, otherwise we might want to switch to something else.

The claim is that kerosene use is harsher than methane—yet Falcon’s Merlin engines seem more trouble free than Raptors.

Many worried about coking deposits—perhaps a factor in shuttle engine choice.

But as you point out—these Falcons have flown about as many times as many orbiters.

Well, yes, coking *is* the problem for kerolox. It’s always going to be a constraint on reuse.

But Merlin 1D is a mature engine. The Merlin has been around in some form for two decades now, and it has been refined and iterated to be an optimized engine. There’s little room to do more with it. It’s an operational piece of hardware, not a development article.

This, however, is not the case with Raptor, which is very much still in development — these are all basically still prototypes. I don’t think it’s fair to compare Raptor to Merlin in this regard, because these are two engines in very different stages of their existence. Raptor 3 has yet to debut on a launch yet, and it is supposed to address a lot of these issues that the Raptor 2 is struggling with.

I have since used it for cleaning a bunch of small metal parts.

I can see using it to blast off soot on Rocket engines.

https://www.spacevoyaging.com/insights/2023/06/22/rocketdyne-f-1-our-golden-chariot-to-the-sky/

The claim is that kerosene use is harsher than methane—yet Falcon’s Merlin engines seem more trouble free than Raptors.

Many worried about coking deposits—perhaps a factor in shuttle engine choice.

But as you point out—these Falcons have flown about as many times as many orbiters.

One of the secrets apparently is the use…of walnuts:
https://forum.nasaspaceflight.com/index.php?topic=63090.200

My parents had a neighbor lady who lived by PREVENTION magazine, Organic Gardening.
She bragged about using walnut hull juice as hair dye.

If Starship can’t work—maybe new shuttles with a prime for the orbiter, but SpaceX engines?

I used to be able to get stats like those – and many others besides – on the site elonx.net, but the site ceased being updated at mid-year and I fear its former proprietor may have passed on.

Richard M: Yes, I intend to include this whenever one of SpaceX’s Falcon 9 boosters moves up in these rankings. I got tired of comparing the two Wikipedia pages to figure it out. This way it is there, easy to see.