Help me understand

[Daff_Duck]

I have touched on this before but don’t quite get it still.

So having predominantly driven Diesel cars for many years and almost always German and 200+ BHP when accelerating the first gear range is so short it takes you to say 15 mph at full revs before you go up the gears.

Now often you have smaller city cars or vans that shoot off and don’t seem to stop. So say I am at the lights I know that a van or city car will beat me to the roundabout or next set of lights due to me having to change gears

I am aware of weight to power ratio and gear ratios. But is this something unique to German cars that the first gear gets you no where. Why do 140BHP vans move so quick even when full. Is it by design that their gear ratio or torque band width is, seemingly so long they are able to pull off and accelerate so quickly?

 

[Resident]

I have touched on this before but don’t quite get it still.

So having predominantly driven Diesel cars for many years and almost always German and 200+ BHP when accelerating the first gear range is so short it takes you to say 15 mph at full revs before you go up the gears.

Now often you have smaller city cars or vans that shoot off and don’t seem to stop. So say I am at the lights I know that a van or city car will beat me to the roundabout or next set of lights due to me having to change gears

I am aware of weight to power ratio and gear ratios. But is this something unique to German cars that the first gear gets you no where. Why do 140BHP vans move so quick even when full. Is it by design that their gear ratio or torque band width is, seemingly so long they are able to pull off and accelerate so quickly?

It's not just German cars however it doesn't seem to apply to small diesel vehicles.

I have a Mondeo with the ST-TDCi engine and first is practically useless in terms of launching. It's ok for crawling but as you describe setting off I'm literally lifting the clutch pedal to then needing to change into 2nd immediately. A friend who has a 1400 TDCi Fiesta doesn't have the same issue, but then it's a slow sack of faeces.

I guess with vans it's a mix of lower end torque and different ratios, they've been designed with the potential weight in mind & the potential stop/start nature of their use

 

[adolf hamster]

i'd wager it's because with the larger engine you're more likely to encounter owners who want to tow things, and therefore you're more likely to want a lower first gear to help get things moving in that case.

 

[sovietspybob]

Practice changing gear faster

But seriously some cars are geared really low in 1st for various reasons which makes them a bit pants at the traffic light GP.

With a petrol engine almost all cars will do 30mph in 1st gear if you want to make a really quick get away.

 

[Mercenary Keyboard Warrior]

Its just gear rations.

When you compare a road car to a van your in effect comparing a car thats designed to be a balance of economy vs usability, vs a van which is designed to carry more load, so it has to have lower gearing and hence will be able to rev faster than the same equivalent car, but come faster speeds the car will be much better.

There are a few cars that take the same principle, lower gearing and lower top speed to the road, I think (cant recally how the models were changed) that the Scooby type RA was the one with the lower top speed and much closer gear ratios, but it may have been the V limited.

You could have your diesel 200BHP+ german car accelerate much faster if you wanted to top out at say 80mph, and halve your fuel economy

 

[Daff_Duck]

Thanks. I did think this ( in the case of vans) it was to do with more torque in order to pull. But thought the principle of having a worthless 1st gear was maybe a German thing

Yes I could hammer it but by the time I hit the “sweet” spot of max torque and power the little guy with the town car has shot down the road

I guess as I have now learned it’s horses for course. My car eats miles but when it comes to town it’s just lags along with the weight and size it’s not designed to rip up back streets and speed down to the shops.

Next stop bike with a side pans on stick my laptop and suit in their and jobs done