MS,
There are so many influencing variables in such a test, I would not contemplate even trying it unless I was paid well, and given precision testing/measuring instruments. Without precision, one could Will the results to see what one wants to see.
It is what it is.
Get my depleted battery to 14.7v pronto and hold it, you SOB alternator. Check.
Meanwell, Check.
198 watts of solar, well you can at least hold absorption voltage for the corect time even if you cant get there fast. Check.
If I go from 16.0mpg on the highway at 65mph to 15.0mpg, for 30 minute duration of getting my 40% battery to 80%, So be it. Could slow down 5mph and get it back.
City driving is too variable.
80% to 100% SOC never takes the same amount of time either, unless every cycle is a "lab" cycle, perfectly recharged under the same exact controlled conditions from the same depletion level as All the cycles before.
MS Since you generator recharge I guess you are curious as to whether you are better off running the generator powering meanwell/powermax rather than employing the alternator.
Again many variables would need to be controlled/considered/compensated for, for an accurate repeatable result.
If you have no issues running the generator when driving, the 40 amp Meanwell or 65 amp powermax can certainly recharge your house battery bank faster from ~70% and ~55% State of charge, Simply because they will seek and hold the ideal absorption voltage, something that one cannot control with the alternator without other modifications. Those % are assuming you alternator can provide 90 amps as you drive, and are also guess-timations.
Do you know How much amperage you alternator delivers into house bank as you drive? What voltage it is allowed to achieve, and for how long? Video it if you cannot see voltmeter and ammeter from drivers seat.
Long term trends could be noticed, If you wanted to notice and C/C/C the variables to some degree.
Perhaps some interesting reading:
http://www.mvtanglewood.com/2017/02/engine-alternator-or-generator-which-is.html
One other thing MS, if this thread is about ultimately saving money, well it comes down to Gas consumed versus battery life in your scenario/usage.
How long did you get from your last set of golf cart batteries? Not very long if I recall correctly. 200 watts of solar on the roof can not only save some load on the alternator, and Generator and 120v chargers, saving gas, but it will likely also extend the lifespan of the batteries by a good factor as it recharges all day long, at some rate, and/or mitigates the discharge from loads present during the day.
So it really comes down to, how soon does that 200 watts of solar pay off?
High amps in the morning when most depleted, and enough Solar (hopefully more than enough) to reach and hold absorption voltage all afternoon= happy long lived batteries one is not constantly fretting about or replacing every 8 or 9 months.
I could not imagine it being bright sunlight, winter or summer, and not having some solar to charge or hold at full charge while my fridge holds beer at 33f, and my Fans keep the internal temps no hotter than outside, while listening to music.