Cal Crutchlow left the Sepang MotoGP test having set the ninth fastest combined lap time, but just 0.369s from the top.
The LCR race winner has played an important role in RCV development since last season and, with Honda's main focus being selection of its 2017 race engine, the Malaysian outing saw Crutchlow again called up to try various designs.
Exactly how many different Honda engines were being used by the factory's five riders at Sepang was unclear.
At opposite ends of the development timeline sit the 2016 even-firing 'screamer' and very latest (uneven firing) 'big-bang'-style engines. Plus, it seems, several specifications in-between.
World champion Marc Marquez said he finished the test with
"two different engines. One more similar to last year's engine and the other more similar to the new engine of Honda".
Crutchlow wouldn't say how many engines were available to him. But the Englishman did confirm he was testing the 'newest spec' - which would suggest an engine used by Marquez and Repsol team-mate Dani Pedrosa - while indicating that at least one other ('big bang') spec was being used by Marc VDS riders Jack Miller and Tito Rabat.
"The plan is different for Jack and Tito than for us. That's for sure. But as you know from the sound of their engine, they are not on last year's bike also," Crutchlow said.
"I spent ages on the newer version, newest spec, that we also used [on day two]. And then I changed back to our old one at the end. It was difficult to switch your head back, because they are so different in terms of characteristic and finding your way.
"I saw Jack on his long run and he rode well with a different spec engine to us and maybe a better spec engine than we have in a few areas... It's also pleasing that we saw Dani and Marc competitive today."
Marquez was second fastest on the final day of testing, just 0.138s behind Yamaha's Maverick Vinales, with Pedrosa in fourth.
"We are happy enough with what we've got and what we've been trying," Crutchlow continued. "We never set the world alight. I had quite a lot of problems with the engine brake of the bike, not being able to stop.
"We know we are losing at least three tenths in that area alone, even compared to Marc and Dani, they have a little something different to be able to do that. So we are quite pleased where we ended up. Not lap time wise, but overall."
Cal Crutchlow's long run:
1. 2m 2.089
2. 2m 1.160
3. 2m 1.198
4. 2m 1.133
5. 2m 0.960
6. 2m 1.693
7. 2m 0.991
8. 2m 1.044
9. 2m 1.018
Crutchlow also did an impromptu long run during the final afternoon, which resulted in him running out of fuel!
"I was not supposed to do any long run, over six laps, and I just kept going! Then I ran out of fuel. I had a really bad tyre that was used and the lap time was pleasantly surprising. We know if we had a decent tyre, and the other allocation tyre, we would have been at least half-a-second quicker a lap. I was pleased because I think we could have done a very long run, 15 laps, in the really low [2min] '0s'.
"And finally we did some back-to-back comparisons with our old bike, which was again pleasing because it confirmed a few things. Now we will sit down with Honda and go through everything."
With one of the three pre-season tests complete, it's getting close to crunch time in terms of selecting the final engine design for the 2017 season, which cannot be changed until the championship is over.
The general feeling is that a different Honda engine should have been chosen last season - a mistake they are determined to avoid repeating, hence the input from the satellite riders and especially Crutchlow.
Crutchlow is the only current Honda rider to have raced for another MotoGP manufacturer, claiming podiums for Yamaha and Ducati before joining LCR in 2015.
"We think it was the wrong direction and had to stick with it all year," Crutchlow confirmed of the 2016 engine.
"We are very grateful for Honda to let us test alongside them with regards to certain aspects of the new bike. But it's only the same as I did during last season when I went to Malaysia, Aragon, and used the [new] engine [again] in Valencia.
"With my experience of the other manufacturers, and my experience of riding this motorcycle, I think they need me to give them the information. It's good for me as well because we are able to see what Marc and Dani are on, to an extent.
"Honda are working very well and they want to see satellite podiums. They want Hondas to finish 1-2-3."
Crutchlow is still using the chassis he race-developed during the second-half of last season, but did try a new fork on day two at Sepang.
By Peter McLaren