RPM O meter

[Ikyuaoki]

does higher RPM offer better performance? i were keeping eye on the RPM meter how the engine is running fast while shifting the manual.

[Twelvefield]

The tachometer measures how many revolutions per minute the engine will produce for the drive shaft. Typically, there's a range that offers the best performance and as a rule of thumb that ought to be somewhere in the middle. The driver's manual will provide the specific numbers.

If you shift up with the tach too low, the engine will lug and can stall because you're not providing enough power the taller gear. If you shift too high, you're wasting fuel and wearing out your engine. Trucks with their fancy dual-clutches have very specific ranges. New trucks have computer-controlled clutches to assist or control shifting because a completely manual transmission can require you to monitor the tach ranges very closely as you drive.

In the game, though, you don't need to watch all that closely, at least for the vanilla trucks that you get. You can tell by engine noise and your acceleration as you drive.

[Leetpandaz]

when you buy an engine it will tell you where the best torque is, mainly its 1100 to 1600 RPM, some engine are 1250-1600 and slight variations like that.

[Mike]

The MX-13 peak torque of up to 1850 lb-ft is at 1000 to 1100 rpm
It's not always good to let it reach the high rpm values.

If you have a PACCAR engine you can shift at +- 1300 ..
If you have a Cummins or a Cat you can give 'em a little more, but not much more.

The only time early downshifts or high rpm values work well is going uphill (or downhill for braking).
Anything else is wasting diesel...

[mook]

i lik to shift at 1500 rpms

[Ikyuaoki]

i'll take this cummins engine for that my truck, i think i have this cummins engine installed in my kenworth W900 truck.

[Ikyuaoki]

Originally posted by Twelvefield:

The tachometer measures how many revolutions per minute the engine will produce for the drive shaft. Typically, there's a range that offers the best performance and as a rule of thumb that ought to be somewhere in the middle. The driver's manual will provide the specific numbers.

If you shift up with the tach too low, the engine will lug and can stall because you're not providing enough power the taller gear. If you shift too high, you're wasting fuel and wearing out your engine. Trucks with their fancy dual-clutches have very specific ranges. New trucks have computer-controlled clutches to assist or control shifting because a completely manual transmission can require you to monitor the tach ranges very closely as you drive.

In the game, though, you don't need to watch all that closely, at least for the vanilla trucks that you get. You can tell by engine noise and your acceleration as you drive.

I do need to watch my RPM tachometer to keep my semi truck humming, higher RPM O meter means better performance and efficient fuel/engine of the rig truck. I found that manual shifting offers better performance than the automatic transmission gearbox.

[Fury6]

All of the engines in the game use the same torque curve. Peak torque is between 1100 & 1400 RPM for *all* engines.

Originally posted by Ikyuaoki:

i'll take this cummins engine for that my truck, i think i have this cummins engine installed in my kenworth W900 truck.

It doesn't matter what make or model of engine you have, they all behave exactly the same. The only output related performance differential between any two engines in the game is their respective torque output maxima. In fact, it seems pretty clear that there really aren't any individual engines - engines aren't being simulated in the game. The individual engine definitions are essentially just parameter input files for a motive-force calculator that the game runs each simulation cycle.
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As of several patches ago the engine configuration does allow for individual torque curve definition of arbitrary data point resolution (ie, each engine can be configured with a unique torque curve definition), however that is yet to be taken advantage of in the vanilla engines.
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The bottom line for fuel efficiency is, basically, shift up as early as you can get away with and shift down as late as you can get away with. Precisely where on the torque curve to shift depends on a range of different factors such as gearbox, terrain, load etc but the basic idea is to shift at the lowest RPM that the next gear can still keep the load accelerating.

For reference, on level terrain with the 13 or 18 speed box you can shift up at around 950 RPM no problem, regardless of load.