DAF Trucks Discussion Thread

[ScaniaMANIveco]

Tried the DAF XD (still retain that CF was a better name) and it was surprisingly enjoyable. At first I was sceptical, since it just seemed like a smaller, less powerful version of the XF/XG/XG+. But it won me over.

[Hetisen]

Guys, is it just me or have they added another symbol to the DAF XG dashboard? Have the collision sensor sounds changed too? I'm talking about the 1.55

[harishw8r]

I remember something along those lines happening in 1.54.

[Crocko From Oz]

Exactly! The transmission makes a difference. It's not only about the engine

It's not the engine HP or the gearbox/final-drive ratio that makes a truck pull a load better … it's the torque that the engine produces, and to a lesser extent the HP rating.

Take the Cummins X15 here in Australia for example. Our Cummins X15 550hp is produced in two variants, a 550hp/1850 lb-ft and a 550 hp/2050 lb-ft. It's quite obvious the 2050 will pull a load better than the 1850 with the same HP rating.

We also have the X15 580 Efficiency Series which is 580 hp/2065 lb-ft, which is slightly above the standard X15 600/2050. Btw, a 'factory' ECU tune (computer remap) for the 600/2050 can increase that to 625/2250 and still be covered by the factory warranty.

One other thing to remember is the SCS "game engine" itself. The SCS engine def doesn't rely on HP whatsoever, it solely relies on its torque figure. A 300/2050 engine will perform exactly the same as a 600/2050 engine.

[Bandit & The Snowman]

Yet the transmission still plays a role, it's the combination of both engine torque and drivetrain ratios that defines the ability to pull. The torque figures you gave are what the engine outputs, that's multiplied by the gearbox and final-drive rations and that's the resulting torque which counts.

[Crocko From Oz]

That is true to an extent, but you need "match" the engines torque curve with your final drive (diff) ratio so that it's operating in its "sweet spot". If you lower the diff ratio too far, you will take the engine out of that "sweet spot", especially in today's computer controlled engines which are tuned for maximum efficiency (emissions) and fuel economy.

Just using Volvo Australia's Euro 6 D17 780 as an example, peak torque is produced in a very narrow 200 rpm rev range - 1000-1200 rpm with +600hp available from 1000 rpm to 1950 rpm, with the maximum 780 hp coming in at 1700 rpm. Ideally, at Australia's max 100km/h (for heavy vehicles) you would want your rig to cruise in that (or around) 1000-1200 rpm "window" for maximum efficiency (Volvo's "economy revs" is actually specified as between 900-1300 rpm).

Obviously, that all gets blown out the window when you get to our 140-150 tonne, quad (4 x trailer) road trains found in the mining areas in northern Western Australia where lower diff ratios (or reduction gears) most definitely rule the roost (they're also limited to only 90km/h as well).

[Winchester1979]

Yet the transmission still plays a role, it's the combination of both engine torque and drivetrain ratios that defines the ability to pull. The torque figures you gave are what the engine outputs, that's multiplied by the gearbox and final-drive rations and that's the resulting torque which counts.

Don't forget wheel size.

Bigger wheels means a faster truck, but with less torque - which means you want a higher diff ratio to give the wheels more torque at the expense of speed. Similarly, smaller wheels means a slower truck, so you want a really low diff ratio to trade some of the torque for more speed.

If you're using mods like Galimim's Drivetrain Revisions and any of the realistic tire mods, you'll hopefully quickly notice that there are some obvious "sweet spots" where a particular combination of engine, gearbox and tire size will basically leave the truck running at idle at 70, 80 and 90 kph in the top three gears, for maximum fuel economy. Change any of the three, though, and you're going to be stuck with a truck that doesn't want to stay in the low end of the RPM range at any "normal" speed, because it wants to shift down to a lower gear constantly.

On the other hand, for some applications you want max pulling power, and running economically at a certain speed becomes a luxury. In that case, you're probably going to want standard-size tires (315/70), the strongest engine, and the gearbox with the highest available diff ratio. With the options available in Galimim's mods, the truck will still reach 80 kph at the top end, but won't like being there... but it will move with just about any load you can find in the game, and will work its way up any hill too.

(and in real life, or with a little bit of modding, you can have the *serious* heavy haul equipment, with diff ratios greater than 7, where the truck tops out at 60 kph but will pull 200 tons...)

[Borgrim]

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[Borgrim]

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[cydonianmystery]

Tried the DAF XD (still retain that CF was a better name) and it was surprisingly enjoyable. At first I was sceptical, since it just seemed like a smaller, less powerful version of the XF/XG/XG+. But it won me over.

The XD is a genuinely solid truck and pleasant to drive. I've actually been surprised that it isn't more popular, especially since it can be configured for either on-highway or rugged applications. A very underrated truck.