What <MR> tag do?

[m1n35weep3r]

Hello there.

When you add true at the very top of a vehicle XML file, what kind of effect does it have?

When I tried adding this to a random tractor mod, I noticed that it no longer suddenly accelerated when I turned the PTO on. In other words, the engine RPM and the actual vehicle speed were no longer directly linked, which made it much easier to work at very low speeds.

However, after the latest update, this effect has disappeared.

I would like to understand the principle behind this — what exactly was happening internally, and why did it work that way before?

[quadural]

Hi,

the problem = which version before and which version after ?
and : are you talking of a cvt tractor or a fixed gear ratios one ?
and : which implement in both cases ?

I would say : no big changes since some weeks. I admit having tuned the CVT transmission in the last updates of the mr engine.
Normal behavior (with mr) = when you turn on a tool with pto, the engine rpm should raise. But the rpm target is different in function of the engine torque curve and the pto ratio and the tool required pto speed.

Example : if the implement pto required speed is "full" (540 rpm in game, because all pto are "540" ish, there is no distinction between 1000 and 540 like irl) and the tractor 540pto speed engine rpm = 2000 => I would say, if the tractor is at still, the engine will rev to something like 1500 ? maybe less
But, if the required PTO speed of the implement is lower, then the engine will rev lower (tractor at still)
Of course, if the required pto speed is 540 and you are moving, the tractor will try to raise the engine to the max pto speed (between 1900 and 2100 on most tractors)

Example IRL :
not enough pto speed for a sprayer = not enough pressure from the pump
not enough speed for a rotary harrow = bad work result
not enough speed for a mower = missing spots or bad mulching of plant residues

being able to run a mower at low rpm would be "cheating" (less fuel consumption, less power needed and higher working speed in some cases)

of course, all I say = with only "mr engine" (no other mods)

[m1n35weep3r]

Both MR versions are the previous one; what I was referring to was the game update itself. When the game changed from 1.15 to 1.16, this phenomenon started occurring.

I wanted to see what would happen if I added the true tag.

The tractor I used was a manual transmission model, and the implement was a sprayer.

As you said, when the PTO is turned on while stationary, the engine RPM shows around 1500 rpm, and when I start moving, the tractor begins to drive at a speed corresponding to that RPM. However, after adding this tag, the engine RPM is effectively ignored, and the tractor starts moving at a speed corresponding to the idle RPM — the same as when the PTO is turned off.

Then, after updating to 1.16, this effect no longer appeared.

So I’m wondering whether this behavior was intentional, and what exactly changes when the tag is enabled.

[quadural]

I suppose there was something else at play : nothing has changed with v1.16 as far as I am concerned
best thing to do if you encounter something "strange" = test the same situation with "mr engine" only (no other mod) and with a base game mr tractor + base game mr implement to check if you can reproduce.
Another point = are you playing with controller or keyboard ? sometimes, it is also a good bet to try with keyboard only (controller unconnected) => we can get a lot of weird behaviors with controller in some situations

to answer what is going on when the MR tag is present :
in script, the variable "self.mrIsMrVehicle" is set to true if the tag is present
=> implement get the "mr attacher setting" (we want to get the same "lowerRotationOffset" whatever the "lowerAlpha" corresponding to the current lower distanceToGround of the implement)
=> fuel usage factor is divided by 2 when the tag is not present (because base game xml settings = about 2 times IRL fuel consumption)
=> engine torque curve can be lowered to simulate transmission efficiency (mainly for harvester in road mode)
=> the prefix "MR" is added to the vehicle name
=> the engine torque curve get 2 new points at the end to simulate the governor range
=> if there is no "mrForcePointRatio" specified for a wheel, the force point is set about 10cm above the ground

[m1n35weep3r]

Thanks!

It seems quite likely that the effect this time was just my misunderstanding.
Also, I’m using a pedal set with a clutch, so that might be related as well.

[Robertszabo1991]

@quadural Greetings, all my respect for this wonderful mod. I also noticed a problem today after the update V20260213. I'm talking about the manual transmission. When it's in neutral, I can't accelerate anymore. The engine only idles. Now it's changed and the clutch no longer starts. The tractor doesn't start after releasing the clutch unless I accelerate the tractor.

[Robertszabo1991]

@quadural Now I installed the previous version and it works perfectly. I don't know if you changed something in the mod or if there's something wrong with the new update.

[quadural]

hi @Robertszabo1991,

the only change in V20260213 = CVTaddon mod.
=> #80 (comment)

So, if you don't own this mod, you should not experience any change.

[Robertszabo1991]

ok thank you