Why do diesels accelerate so slowly even with high torque?

[Cerano]

Yap, even new Benz cab also noisy from the outside. I wonder is it because of the design of what, generally diesel cars are noiser, if not, it is just a matter of time, IMHO.

 

Regards,

 

mercedes engine tend to be very loud!!!! ):

[Kelpie]

i wonder if that 3.0L turbo diesel can outgun a 2.0T

 

Without talking about the made, for street racing, will depend on the driver. But straight line racing, it will be tough for the lower cc car.

 

Regards,

 

 

[Cerano]

Without talking about the made, for street racing, will depend on the driver. But straight line racing, it will be tough for the lower cc car.

 

Regards,

 

drag racing bro.

 

2.0T petrol vs 3.0 TDI

 

2.0T will win im pretty sure

[Kelpie]

drag racing bro.

 

2.0T petrol vs 3.0 TDI

 

2.0T will win im pretty sure

 

Power to weight ratio again and the suspension at work when concurring tight corners. You don't need a 2.0T to win a TDI. Driver counts too.

 

Regards,

[Tom_kkh]

the thing that affect a bar from point a to b is bhp, of course other factors too.

 

Torque means how many ppl u can carry without affecting the speed,

 

eg yr car goes from 0 to 100 in 6 secs, with only u in the car. But with 4 ppl, it takes 8 secs. But if yr torque is high it will take the same amt of time.

 

So higher torque doesnt neccessary means faster. It meant how many ppl u can take in the car without affecting the preforamnce.

 

Layman term...

[York]

hmmm....it's outdated by half a decade liao. today euro4 diesel engines are turbo-charged

 

take a look @ the lower capacity euro4 engine, below 2L, ie eurovan...it can take most of the 1.5 or 1.6L petrol power car. Some more their fuel efficency is superb, most are able to clock more then 15km/L.

[Cerano]

hmmm....it's outdated by half a decade liao. today euro4 diesel engines are turbo-charged

 

take a look @ the lower capacity euro4 engine, below 2L, ie eurovan...it can take most of the 1.5 or 1.6L petrol power car. Some more their fuel efficency is superb, most are able to clock more then 15km/L.

 

1.5L 1.6L NA car but like SC 1.6L or TC 1.6L cannot match at all

[Joseph22]

1.5L 1.6L NA car but like SC 1.6L or TC 1.6L cannot match at all

 

Diesels engine in europe is for good FC. Think you can stop comparing the speed liao. totally different from the maker idea of Diesel engine.

[Mingsect]

put in more gears for top speed lor

 

even u put in more gear.

the output of the engine must be enough.

to overcome the drag, wind resistance of the vehicle in order to increase the top speed

[Boyboy]

oic because articles all say very low hmm....

 

but how's your acceleration bro? does the torque make a diff

 

i guess. for a miserable 100bhp stock, it sure runs like hell. but the torque is 240nm.

[Boyboy]

ok la.

their 0-100 slow >7s not that power despite their super high torque

 

true. i think more like 8+ or even 9+ seconds.

 

but the initial torque will get them off the line very fast. petrol power comes in at high revs. so for diesel 8s and petrol 8s, the diesel will still embarrass the petrol off the lights. of course top speed no horse run lah, confirm petrol engine way ahead eventually, then the diesel will slowly build up to top speed.

 

top speed is bhp and gearing.

[Cerano]

true. i think more like 8+ or even 9+ seconds.

 

but the initial torque will get them off the line very fast. petrol power comes in at high revs. so for diesel 8s and petrol 8s, the diesel will still embarrass the petrol off the lights. of course top speed no horse run lah, confirm petrol engine way ahead eventually, then the diesel will slowly build up to top speed.

 

top speed is bhp and gearing.

 

I used 100km/h because that is pretty slow normal highway speed bro

 

nowhere near top speed

[Boyboy]

drag racing bro.

 

2.0T petrol vs 3.0 TDI

 

2.0T will win im pretty sure

 

eventually. initial the petrol confirm lose. but depends on what one wants.

 

i play with some souped up civics before. the old sir type and new type R. can keep up with them in the initial phase, and my displacement less than the 2.0 type R. eventually cornering and flat out will lose big time la, i'm not kidding anyone here.

 

driver skills wise, i dunno abt the type R, but my launching is horrible. loads of wheelspin. with 195 tires and 240nm stock (now zhng maybe 280 or more), hard to maintain traction

[Cerano]

eventually. initial the petrol confirm lose. but depends on what one wants.

 

i play with some souped up civics before. the old sir type and new type R. can keep up with them in the initial phase, and my displacement less than the 2.0 type R. eventually cornering and flat out will lose big time la, i'm not kidding anyone here.

 

driver skills wise, i dunno abt the type R, but my launching is horrible. loads of wheelspin. with 195 tires and 240nm stock (now zhng maybe 280 or more), hard to maintain traction

 

actually displacement alone doesnt count here.

 

the diesel will run out of breath at high speeds

[Mini-itx]

okay so... if the peak torque isnt for acceleration then it doesnt count for much....

 

Torque and power is closely related.

 

Torque is needed for acceleration. More torque = accelerate faster.

 

Horse Power or HP = Work Done over time (Physics here).

[Mini-itx]

actually displacement alone doesnt count here.

 

the diesel will run out of breath at high speeds

 

Thats where gear ratios comes into play. Diesel engine runs out of power at high RPMs, but they can just shift to higher gears and they get the power already.

[Mini-itx]

Btw, I have to stress one thing. All these figures you are looking are just peak HP/Nm figures.

 

Whats really important is not the peak but the curve. Why diesel cars can pick up really fast is because of high torque at low PRMs. For petrol cars, the torque at low RPMs is much lower. You only hit peak at around 4-5K RPM.

 

For high performance NA cars like Honda CTRs etc, its even worse, peak comes in only at arounf 6-7K RPM.

 

Thus if both petrol cars and diesel are idling and then floor throttle to move, diesel cars always pick up faster. Only when revs goes up then petrol car can catch up as torque increases with rpm. Btw, launching at specific RPM is different story.

[Coupecabriolet]

but diesels can go up to over 200kmh

 

its true their top end is crap... but their low end acceleration like 350nm TDI takes 8.1 seconds

 

http://www.themotorreport.com.au/30082/vol...25kw-tdi-engine

 

VW sciroco GT 350nm takes 8.1 secs thats not very fast given its 350nm torque

 

bro scirocco GT 350nm is the 2L version. 1.4L version with SC and TC has only 240nm of torque and century sprint is indeed 8.1seconds or 8s in other reviews.

 

2L version with TC gives around 7-7.1s for 0-100km/h.