Coaches and gears

I sat in front row of coach today so saw drivers cabin.

It was automatic (Neoplan single decker coach 11 plate)

Had 12 gears, and 12th was engaged at 50 mph on flat road. Interestingly it pulled off in 3rd. Are 1 and 2 just for hill starts?

The rev counter only went to 3000 rpm, never saw him go over 2000, and normally kept it between 900 and 1500.

Why does it rev so low and why so many gears?

Was also impressed how quickly it got to the 99kmh limiter- clearly had a lot more to give

Reply 1

JVD

I'm assuming (could be wrong) that there could be different "sets" of gears, like on a mountain bike.

i.e There could be 3 sets of 4 gears, so it might've pulled off in 3rd gear of the 1st set, as it didn't need a smaller gear (therefore more revs) to get going from standing.

Someone else might have a more definitive answer.

Reply 2

Schleigg

My landie autobox always pulls away in second unless you give it some welly and it drops down to first. I suspect you are right about the coach, where then first and second hears are for heavy starts.

Reply 3

InArduisFouette

1. gears - generally in a LGV or PCV you will be pulling away in a gear other than first, as first and sometimes second are crawler gears - this starts to kick in with max weight cat B vans and almost certainly with C1and D1 vehicles

2. truck / bus diesel engines while considered 'high speed' rev lower than car / light van diesles which in turn rev lower than Petrols this is a function of the rotating masses and theneedsto cope with the compression ratios of diesel engine vs a spark ignition engine .

'medium speed' diesels run at a few hundred RPM and the big cathedral like slow speed diesels in ships run at 60 -120 rpm but a slow speed diesel has cylinders you could climb in andpistons the size of a dustbin (or bigger)

3. 900 -1500 rpm for truck / bus engine is the peak torque band - many car / light van application diesels have peak torque between 1500 and 2500 rpm - the torque curves are often very flat in that area

Reply 4

Alfissti

Original post by FuelBowser

We used to charter luxury coaches from a company that operated a fleet of Neoplans, it was equipped with a MAN TipMatic gearbox. I think it was a year or two in age. When it was unladen it could takeoff on 4th gear and didn't require any driver input to do so as it had weight sensors to determine what was the optimum gear.

Diesel engines for heavy vehicles generally have very low RPM range as most of its torque can be delivered at low range which is required for such a vehicle.

Not all of them has as many gears, that company also has one that is a manual and it only has 6 gears. Lots of gears as each of those gears are fairly close in ratios.

Pretty good coaches but now no longer use them as prefer a company that uses Volvo coaches instead. Quite interesting, this one their vehicles has a tracking feature that their manager could know if a driver revs the engine past the green zone even if the coach is many thousand km away from their office.

Reply 5

FuelBowser

Original post by Alfissti

did you ever drive a coach yourself? i wonder if the driver has to floor it wherever he goes because it is so slow

Reply 6

Alfissti

Original post by FuelBowser

did you ever drive a coach yourself? i wonder if the driver has to floor it wherever he goes because it is so slow

Tried driving one a few months ago. Was a Volvo 9900. You don't need to floor it. If you floor it on the 1st to 3rd gear it will be very jerky as well.

Some companies have trackers that if you floor it you lose your fuel efficiency bonus. Most also have blackboxes these days to monitor just about everything that happens with that vehicle.

Reply 7

FuelBowser

Original post by Alfissti

Takes the fun out of it :P

What you reckon they could do flat out? Ours pulled impressively well up to the limiter

Reply 8

Alfissti

Original post by FuelBowser

Takes the fun out of it :P

What you reckon they could do flat out? Ours pulled impressively well up to the limiter

They could easily do 140kph without trying.

Well companies do place those trackers for safety and economic reasons, heavy vehicles do consume lots of fuel.

Reply 9

CurlyBen

A typical modern tractor will have something like a 6 range, 4 speed transmission, with a shuttle lever so you don't select a reverse gear (you just move the lever in the direction you want to go - in theory this means you have all gears available in forward or reverse, though in practice the top gears are not permitted by the software when reversing). Lightly laden you can quite happily pull away in E2 or E3, which is effectively gear 18 or 19. Even heavily laden you'll probably pull away in gear 12 or so! The lowest gears are mainly for maneuvering or really heavy traction.

Reply 10

FuelBowser

Original post by Alfissti

They could easily do 140kph without trying.

Well companies do place those trackers for safety and economic reasons, heavy vehicles do consume lots of fuel.

What kind of MPG do the coaches and the vans give?

Reply 11

Alfissti

Original post by FuelBowser

What kind of MPG do the coaches and the vans give?

The latest Volvo 9900 6x2 that we last chartered on average returned 20-35l/100km depending on load and road situation.

Sprinters, we have several versions. All are either long or extra long wheel base. 4x2 ones are 2.2 or 3.0l while 4x4 ones are only 3.0l and all are automatic. Fuel consumption for the 2.2l EWB one when laden is around 10l/100km while the 4x4 ones are around 12l/100km