Motoring Discussion > Gears, revs, and ability of engine to 'pull'	Miscellaneous
Thread Author: tyro	Replies: 47

New Mon 7 Mar 11 21:13   Gears, revs, and ability of engine to 'pull' - tyro

I suspect that this is another stupid question from me, but here goes. People often refer to the ability of their car to 'pull' from (say) 1500 rpm. It may be my imagination, but I have always felt that engines pull from lower revs if they are in a lower gear. In other words, an engine that doesn't really pull below 1500 revs in 5th gear will pull satisfactorily from (say) 1200 revs in 2nd gear. Is it my imagination? And if so, does anyone know have any idea why I might be under this misapprehension? Reply to this message | Report message

New Mon 7 Mar 11 21:40   Gears, revs, and ability of engine to 'pull' - PhilW

"Is it my imagination?" Don't think so - I can't explain it properly but surely that's the point of the gears - lower geargives better "leverage" as it were - otherwise we would only need one - 6th! I know that on my bike I pull better from a lower gear at low revs! Reply to this message | Report message

New Mon 7 Mar 11 22:17   Gears, revs, and ability of engine to 'pull' - tyro

"surely that's the point of the gears - lower gear gives better "leverage" as it were - otherwise we would only need one - 6th!" If I may put it in my "mechanically incorrect" (or "non-MC", if you prefer) way, I thought that the point of gears was to enable one to get the engine to the appropriate number of revs for the speed at which one is driving - but that the same number of revs would be required to pull the car along, irrespective of what gear one was in. If you see what I mean. Last edited by: tyro on Mon 7 Mar 11 at 22:18 Reply to this message | Report message

New Mon 7 Mar 11 22:25   Gears, revs, and ability of engine to 'pull' - Zero

>> If I may put it in my "mechanically incorrect" (or "non-MC", if you prefer) way, >> I thought that the point of gears was to enable one to get the engine >> to the appropriate number of revs for the speed at which one is driving - >> but that the same number of revs would be required to pull the car along, >> irrespective of what gear one was in. If you see what I mean. Thats one reason. The other the ability to do work. Its exactly the same as the block and tackle. You cant lift a weight by simply pulling on a rope over a pulley, but you can if you use a block and tackle. Reply to this message | Report message

New Mon 7 Mar 11 21:43   Gears, revs, and ability of engine to 'pull' - Tooslow

Ride a bike for a few hundred yards. You'll soon find how gears work. For pulling power you need high torque at low revs. BHP gets you nowhere. John Reply to this message | Report message

New Mon 7 Mar 11 21:48   Gears, revs, and ability of engine to 'pull' - Manatee

>> For pulling power you need high torque at low revs. BHP gets you nowhere. High torque at high revs beats high torque at low revs. The more power, the more progress. Tyro's right though. His observation passes the logic test. Reply to this message | Report message

New Mon 7 Mar 11 21:52   Gears, revs, and ability of engine to 'pull' - Tooslow

You want both. you want a torque curve like Table Mountain. John Reply to this message | Report message

New Mon 7 Mar 11 22:15   Gears, revs, and ability of engine to 'pull' - Old Navy

Easily summed up in one word, "diesel". Reply to this message | Report message

New Mon 7 Mar 11 22:55   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

There are two routes to describe how the engine's output manifests itself as acceleration of the vehicle; a power centric view, and a torque centric view. They are both absolutely consistent with each other, as, after all, power, speed and torque are inextricably linked together. These views or approaches differ mainly in how the gearing affects the quantity ---------------------------------------------------------- First, the power centric view. The gearing does not modify power at all. If you had a 100% efficient transmission, and a 100 BHP engine, you would get 100 BHP at the driving wheels. For a typical manual gearbox system, the efficiency is about 95%, so, you would get 95 BHP. At any road speed and condition, you need to supply a certain amount of power at the wheels to overcome the various sources of drag - rolling resistance, gradient, and aerodynamic drag. If there is more power being delivered to the wheels than the vehicle's drag power, the vehicle will speed up, and vica versa. Some maths Taking Newton's Second law - F=ma multiply both sides by vehicle velocity Fv=mav P=mav The product Fv is the power at the wheels available for acceleration (Power at the wheels minus drag power). Re-arranging gives a = P/(mv) This formula tells us that; owing to the v on the denominator, for a given power at the wheels, the acceleration you get reduces as the vehicle speeds u[ owing to the P on the numerator, for a given road speed, if you can gear the engine to be turning at a speed where it produces more power, you'll get more power at the wheels, and so, you will accelerate more strongly. ----------------------------------------------- Now the torque centric point of view When the engine's torque is passed through a reduction ratio in the gearbox, the output shaft will turn more slowly, but, the torque will be multiplied up by an equivalent ratio. Again, the transmission efficiency takes it's share. So, if you had 100Nm of torque, and a 10:1 overall gear ratio, you would get 1000 Nm at the wheels with perfectly efficient transmission, but, only 950 Nm if the efficiency were 95%. Taking the torque at the wheels, and dividing by the rolling radius of the wheel gives the tractive effort - the force pushing the vehicle along. If we subtract all the sources of drag force from the tractive effort, and are left with a positive value, the vehicle will accelerate, and vica versa. Again, starting with Newton's Second Law F=ma If we consider F to be the net force - tractive effort minus drag force, then, that's it, Newton's Second Law tells all. We can, however, look a bit further, and split up the left hand side of that equation, and look at the tractive effort and the drag force, fd; TE-fd=ma (where TE stands for tractive effort) The tractive effort is the engine's torque multiplied up by the gear ratio, divided by the rolling radius (t*ng*nf*eta)-fd=ma where ng is the gearbox ratio, nf is the final drive ratio, and eta is the transmission efficiency Here's where Tyro's question can be seen most clearly - in lower gears, ng is higher. 1st gear ratio in a typical car's gearbox is somewhere in the region of 3.5 to 4, while top gear may be 0.8 or 0.9. So, changing down increases ng, and providing that the engine's torque doesn't simultaneously reduce by more than the gear ratio step, then, the vehicle will accelerate faster. --------------------------------------------------------- Finally, to repeat a point from earlier - the two approaches give exactly the same answer, they are entirely equivalent. Reply to this message | Report message

New Tue 8 Mar 11 07:13   Gears, revs, and ability of engine to 'pull' - Hard Cheese

Reckon the easiest explanation is to say that a larger /more powerful engine will pull a higher gear as easiliy as as small / less powerful engine wil pull a lower gear. In the same way that a fit and strong cyclist can cycle up a hill in a high gear at a reasonble speed where as the average Joe on the same bike would have to change down a few gears and travel up the hill much more slowly with legs spinning at the same rate if not faster. Reply to this message | Report message

New Tue 8 Mar 11 08:29   Gears, revs, and ability of engine to 'pull' - tyro

Thanks everybody. It's good to know that it is not my imagination. It's also good to see Number_Cruncher's mathematical explanation, even though it's all Greek to me*. Am I therefore correct in assuming that if a car has a particularly tall top gear, it means that the car will not pull as well in top gear at low revs as it would if the car didn't have such a tall top gear? (*The explanation for my obtuseness is that even though I did a degree in biological sciences, and did pretty well at the chemistry and statistics I did in first year at university, I didn't even do physics to O Level. Perhaps I should add that when doing O and A level maths, I managed to avoid those bits of the syllabus that covered mechanics. And then there is the fact that I was never interested in machinery and how it worked, and nor was I practical or good with my hands. So I reckon that when it comes to the award for C4P mechanical numpty, I will not have much competition.) Last edited by: tyro on Tue 8 Mar 11 at 08:33 Reply to this message | Report message

New Tue 8 Mar 11 09:59   Gears, revs, and ability of engine to 'pull' - Cliff Pope

Another observation is that the torque and power "curves" are peculiar to the car/gearbox/engine combination, and after a lot of driving you begin to get the feel of how it pulls in different circumstances. Sometimes the torque comes in with a rush at a particular point, but is feeble until you reach the critical point. Some run out of steam above a certain point, others go on pulling. I can always judge the differences between my cars by how they perform climbing a particular hill on my way home. For example if a pass a particular cottage half way up at 35 mph or more in 3rd, it will pull strongly up the remainder of the hill even though it gets steeper. But if I fail to hit 35 then the speed quickly drops and I need 2nd. One of the 2 Volvos does it easily, the other with slightly different engine and gearbox type needs about 38 mph to do the same thing. The old Triumph, with a straight 6 engine, would pull up at a steady 30 mph in top gear. Some cars are more affected by load than others. Any weight up to about half a ton makes no difference to the Land-Rover. But 2 passengers have a big effect in the small Peugeot. Reply to this message | Report message

New Tue 8 Mar 11 11:26   Gears, revs, and ability of engine to 'pull' - Stuartli

My VW 1.4 TSI petrol engine (168bhp) can deliver/delivers 100 per cent of its 177lb ft of torque from around 1,750rpm to 4,500rpm and then at least 80 per cent of the torque from that point to 6,000rpm - it pulls just like a diesel... See: www.evo.co.uk/carreviews/evocarreviews/67063/volkswagen_golf_gt.html However, the top speed can only be reached in fifth rather than sixth gear (not that I've ever had chance to try!) and is where, as I understand it, the 168bhp would play the key role. Last edited by: Stuartli on Tue 8 Mar 11 at 11:28 Reply to this message | Report message

New Tue 8 Mar 11 12:22   Gears, revs, and ability of engine to 'pull' - Stuartli

PS Even "caning" the Jetta Sport, the TSI returns at least 39mpg and can easily return 45mpg+ when used more gently. Reply to this message | Report message

New Tue 8 Mar 11 12:56   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

>> Am I therefore correct in assuming that if a car has a particularly tall top >> gear, it means that the car will not pull as well in top gear at >> low revs as it would if the car didn't have such a tall top gear? Yes. If you had an infinitely variable gearbox, and you wanted the very best acceleration, you would adjust the gear ratio to make the engine always turn at its maximum power speed - any faster, or any slower, and the acceleration will reduce from this theoretical optimum. Reply to this message | Report message

New Tue 8 Mar 11 13:10   Gears, revs, and ability of engine to 'pull' - Cliff Pope

>> >> >> >> If you had an infinitely variable gearbox, >> >> As indeed some do, or did. I knew someone with a Daf 44 with the variomatic gearbox, if that was its name. It felt really odd, a bit like driving a car with slight clutch slip. It made a constant noise a bit like an automatic that has just changed gear, which of course it was in a way. Reply to this message | Report message

New Tue 8 Mar 11 15:46   Gears, revs, and ability of engine to 'pull' - Stuartli

>>I knew someone with a Daf 44 with the variomatic gearbox, if that was its name.>> I recall driving the Fiat Tipo or Punto (?) version of this (Continuously Variable Transmission - CVT) in the early 1990s; the Daf belts were replaced by steel belts for greater reliability. It was quite weird to drive as you have recalled, giving the impression it was always searching for a higher gear. Ford (and Nissan?) also had versions of the system, but it never proved popular. The CVT was first seen in 1987 on the Uno and was developed in conjunction with Dutch Van Doome and Ford. Reply to this message | Report message

New Tue 8 Mar 11 15:28   Gears, revs, and ability of engine to 'pull' - BiggerBadderDave

"If you had an infinitely variable gearbox" Like this one? You keep waiting for it to change gear but it never does. www.youtube.com/watch?v=DFmvPhza1go&feature=related Reply to this message | Report message

New Tue 8 Mar 11 16:22   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

>>Like this one? Yes, that's the type of thing. That motor was fairly shifting! >>You keep waiting for it to change gear but it never does. It's actually changing "gear" all the time though! As most people are used to discrete gears, and the need to keeping changing up as they accelerate, CVTs tend to confuse most experienced drivers as they associate acceleration with changing engine note, while, actually, the CVT is likely to be far outperforming a car with a standard discrete ratio gearbox. We've seen how with a CVT, you get maximum acceleration when the engine is held near the maximum power speed. However,.... If you have a conventional gearbox, and you accelerate through the rev range, and don't change gear, you get the most acceleration when the engine is at the speed where it produces maximum torque. Reply to this message | Report message

New Tue 8 Mar 11 16:43   Gears, revs, and ability of engine to 'pull' - Hard Cheese

>> However,.... >> >> If you have a conventional gearbox, and you accelerate through the rev range, and don't change gear, you get the most acceleration when the engine is at the speed where >> it produces maximum torque. >> >> NC, is that right? the engine speed where it produces most torque is where each individual cycle is strongest. Though surely you would acheive maximum acceleration at the point where the engine speed is where it produces most power, i.e. where the torque x revs curve peaks? Of course this does not account for aero etc factors as the vehicle accelerates, the max power road speed being as much as three time or so of the max torque road speed in the same gear. Reply to this message | Report message

New Tue 8 Mar 11 16:45   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

>>NC, is that right? Yes! That it might seem odd, especially after the CVT discussion, is exactly why I bothered to post it. Reply to this message | Report message

New Tue 8 Mar 11 18:10   Gears, revs, and ability of engine to 'pull' - Hard Cheese

>> >>NC, is that right? >> >> Yes! >> >> That it might seem odd, especially after the CVT discussion, is exactly why I bothered >> to post it. >> I need more convincing NC, I am not saying you are wrong though can you explain? Reply to this message | Report message

New Tue 8 Mar 11 21:28   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

It's perhaps easiest to explain using a torque centric view. When you are in a particular gear, the gear ratio, the final drive ratio and the rolling radius remain constant. Therefore, as you accelerate through the rev range, the tractive effort is always proportional to the engine's torque. Therefore, you get maximum tractive effort when you get maximum torque. As F=ma, you get maximum* acceleration at the engine speed where you get maximum torque. Taking a power centric point of view, if you look at the available power equation above, you'll see that there's v in the denominator for the expression for acceleration. Therefore, as revs increase, if the power does not rise faster than the velocity, the acceleration will be reducing - for power and velocity to be increasing in step requires constant torque. Once you're beyond peak torque, power does not increase in step with velocity, and, so, acceleration is reduced. ---- There is the tiniest most pedantic error - as the drag increases with speed, the peak acceleration actually occurs just *below* the peak torque engine speed. The error is very small, and is pedantic in the extreme. I don't have time to check now, but, I'll be surprised if it's more than 50 rpm for a typical car. ---- As before, the power centric view and the torque centric view both tell the same story - they are both consistent ways of saying the same thing Reply to this message | Report message

New Tue 8 Mar 11 21:58   Gears, revs, and ability of engine to 'pull' - Hard Cheese

Thanks NC, interesting. Again I am not sure though bearing in mind that for power to increase above the power produced at peak torque rpm the torque drop off has to be less than the corresponding increase in rpm. I.e. if an engine produces its max torque of say 100lb ft at 3000rpm, at 4500rpm the engine may only produce 75% of its maximum torque i.e. 75lb ft however in power terms the 1.5 fold increase in engine speed needs to be accounted for hence the engine is producing more power at 4500rpm than at 3000rpm even though it is producing less torque. To put it another way while the size of the punches are less a higher RPM the fact that there are more punches more than compensates, surely in acceleration terms this means that acceleration is increased along with the increase in revs. In this regard some engines (turbos etc) have very steep power curves where the torque is sustained (albeit a little below maximum) as the revs rise hence the rate of acceleration increases quickly as the revs rise whereas other engines have a shallow power curve giving a very linear rate of acceleration at best. Of course if the torque drop off as the revs increase is truly linear then the power would be constant thoughout the rev range. Reply to this message | Report message

New Tue 8 Mar 11 22:10   Gears, revs, and ability of engine to 'pull' - John H

>> the power produced at peak torque rpm >> acceleration >> some illustrations here craig.backfire.ca/pages/autos/horsepower www.fjr1300.info/misc/torque-power.html autospeed.com/cms/title_Power-versus-Torque-Part-2/A_108648/article.html www.allpar.com/eek/hp-vs-torque.html auto.howstuffworks.com/auto-parts/towing/towing-capacity/information/fpte3.htm Last edited by: John H on Tue 8 Mar 11 at 22:12 Reply to this message | Report message

New Tue 8 Mar 11 22:45   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

>>www.fjr1300.info/misc/torque-power.html That's a page which I'm broadly in agreement with. It's interesting to note that what is written there as myth #3 is quite similar to the statement I made above, BUT, I was careful to make the qualification that the car stays in the same gear, and we are simply comparing the acceleration we get at various points in the engine's rev range. There's no contradiction between my point, and what's written on that page. I like the criticism of inertia dynamometers written there too - I'm not a fan of them. Reply to this message | Report message

New Tue 8 Mar 11 23:03   Gears, revs, and ability of engine to 'pull' - Hard Cheese

>> >>www.fjr1300.info/misc/torque-power.html >> >> That's a page which I'm broadly in agreement with. >> However NC it says "If the gear ratios are properly matched to that torque curve and the wheel speed is within the normal operating range, it will always be true that the acceleration will be greatest when the engine speed is higher than the engine speed at which the torque peak occurs." Reply to this message | Report message

New Tue 8 Mar 11 23:06   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

Yes, that web page is saying that you change gear to acheive that condition - I'm describing what happens when you stay within one particular gear. Reply to this message | Report message

New Tue 8 Mar 11 22:34   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

>>Again I am not sure In gear, tractive effort is just the engine's torque scaled by the gears and the rolling radius - as F=ma, there's literally no more to it. >>To put it another way ... In looking at the situation from a power centric point of view, you may be forgetting the v on the denominator in the equation for acceleration. a=P/(mv) As you increase engine speed, for the power to grow in step with the vehicle's road speed, requires the engine to produce constant torque. If, as the engine speed increaes, the torque is reducing (as it must once you're beyond peak torque), the denominator grows quicker than the numerator, and, thus, acceleration reduces. Reply to this message | Report message

New Tue 8 Mar 11 23:16   Gears, revs, and ability of engine to 'pull' - Hard Cheese

>> As you increase engine speed, for the power to grow in step with the vehicle's road speed, requires the engine to produce constant torque. >> Though if the torque can be sustained at say 90% of peak as the revs rise the power would growing ahead of the vehicle's road speed. For this not to happen the torque drop off would have to be greater than the rpm increase surely? >>If, as the engine speed increaes, the torque is reducing (as it must once you're beyond peak torque), >> However if the torque drops off very slightly it is possible for the power to grow quickly relative to the increase in rpm therefore the power can grow quickly over a very small increase in vehicle speed, i.e. from 2500 to 3000 rpm at 20mph/1000 would be a speed increase of 50mph to 60mph over which range the power might increase by 50% thus the acceleration would surely increase as well? Reply to this message | Report message

New Tue 8 Mar 11 23:22   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

>>Though if the torque can be sustained at say 90% of peak as the revs rise the power would growing ahead of the vehicle's road speed. For this not to happen the torque drop off would have to be greater than the rpm increase surely? No, that's the point - for power to keep pace with vehicle speed, torque must be constant - ANY reduction in torque will reduce the vehicle's acceleration - hence, maximum in gear acceleration at the engine speed for peak torque. >>thus the acceleration would surely increase as well? No. Let's go back a bit. i) Do you accept the torque centric view? ii) Do you accept that it is equivalent to the power centric view? Reply to this message | Report message

New Tue 8 Mar 11 23:41   Gears, revs, and ability of engine to 'pull' - Hard Cheese

>> >> No, that's the point - for power to keep pace with vehicle speed, torque must be constant - ANY reduction in torque will reduce the vehicle's acceleration - hence, maximum in gear acceleration at the engine speed for peak torque. >> NC, it doesnt seem right to me, though I admit I dont have the answer. Perhaps something is missing - the fjr1300 link posted earlier refers to maximum acceleration being at the wheel speed for peak torque, and as I quoted above says: "If the gear ratios are properly matched to that torque curve and the wheel speed is within the normal operating range, it will always be true that the acceleration will be greatest when the engine speed is higher than the engine speed at which the torque peak occurs." Reply to this message | Report message

New Tue 8 Mar 11 23:17   Gears, revs, and ability of engine to 'pull' - Manatee

>>the denominator grows quicker than the numerator, and, thus, acceleration reduces. There's an if there isn't there? Many turbo diesels now have almost flat torque from 2000-4000 rpm, which may be what Cheddar had in mind - in which case the power is almost proportionate to rpm. Last edited by: Manatee on Tue 8 Mar 11 at 23:19 Reply to this message | Report message

New Tue 8 Mar 11 23:23   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

>>flat torque from 2000-4000 rpm Yes, absolutely, if you had truly flat torque, you would get a rev range where you would get constant acceleration. Reply to this message | Report message

New Tue 8 Mar 11 23:39   Gears, revs, and ability of engine to 'pull' - Stuartli

>>Yes, absolutely, if you had truly flat torque, you would get a rev range where you would get constant acceleration.>> Which is why my TSI unit is so remarkable..:-) But the TSI engine range did win the European Engine of the Year for five years on the run and (probably) still counting... Reply to this message | Report message

New Tue 8 Mar 11 23:40   Gears, revs, and ability of engine to 'pull' - Hard Cheese

>> >>flat torque from 2000-4000 rpm >> >> Yes, absolutely, if you had truly flat torque, you would get a rev range where >> you would get constant acceleration. >> But NC surely you are ignoring the rpm increase multiplier, as long as the increase in rpm is greater that the reduction in torque then acceleration will increase, surely? So a yes a flat torque curve would offer a rapid increase in accleration as the rpm increase multiplies the torque however even if the torque reduces surely the acceleration would increase as long as the rpm increase multiplier offsets the reduction in torque? Reply to this message | Report message

New Wed 9 Mar 11 14:35   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

I'll try again; Let's go back a bit. i) Do you accept the torque centric view? ii) Do you accept that it is equivalent to the power centric view? Reply to this message | Report message

New Wed 9 Mar 11 14:42   Gears, revs, and ability of engine to 'pull' - John H

IIRC, Cheddar had a similar discussion with you on this on Honestjohn's forum. Reply to this message | Report message

New Wed 9 Mar 11 14:45   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

You do remember correctly! Reply to this message | Report message

New Wed 9 Mar 11 17:09   Gears, revs, and ability of engine to 'pull' - Hard Cheese

>> You do remember correctly! >> Similar though I dont recall you saying that maximum in gear acceleration is at the engine speed for peak torque. It is this I am not sure about. Reply to this message | Report message

New Wed 9 Mar 11 21:11   Gears, revs, and ability of engine to 'pull' - Number_Cruncher

>>I dont recall you saying that maximum in gear acceleration is at the engine speed for peak torque I did - a couple of times. When you put the idea back to back with the statement that for maximum acceleration from a CVT demands that the engine be held at maximum power speed, it usually raises a few eyebrows. The statements look, at first sight, to be contradictory, but, they're both correct. Reply to this message | Report message

New Tue 8 Mar 11 17:08   Gears, revs, and ability of engine to 'pull' - R.P.

My dad had a pretty little Volvo 66 - with teenage exuberance I could outdrag most things, including a P6 Rover, from traffic lights, it was noisy but between 30 and 50 there was little that could keep up with it. Reply to this message | Report message

New Tue 8 Mar 11 17:13   Gears, revs, and ability of engine to 'pull' - Focusless

How did the old CVTs decide which 'gear' to select - was it just a mechanical mechanism? Was there any guarantee it was optimal? Reply to this message | Report message

New Tue 8 Mar 11 13:11   Gears, revs, and ability of engine to 'pull' - L'escargot

In general, diesels are higher geared than similar size petrols. This means that for a diesel the torque at the driving wheels is a lower proportion/multiple of the quoted engine output torque than it is for a petrol. Make of that what you will. Reply to this message | Report message

New Tue 8 Mar 11 14:24   Gears, revs, and ability of engine to 'pull' - Tooslow

But you don't mention a critical factor L, which is that a diesel engine of any given size will normally produce more torque than a petrol engine. So if you are using, say, 50Nm, as you pull away that's a smaller fraction of the 300Nm available from your diesel than it is of the 100 or so from your petrol engine. But it's still 50Nm whichever way you look at it. What you have up your sleeve is not relevant. Of course if you have a VAG turbo 1.4 petrol you're well endowed with torque, as Stuartli has said. But what has that got to do with the price of bananas? John Last edited by: Tooslow on Tue 8 Mar 11 at 14:24 Reply to this message | Report message

New Tue 8 Mar 11 23:17   Gears, revs, and ability of engine to 'pull' - Stuartli

>> Of course if you have a VAG turbo 1.4 petrol you're well endowed with torque..>> It's the supercharger that makes the (early) difference because the maximum torque is available from barely more than tickover when called upon. Reply to this message | Report message

New Wed 9 Mar 11 09:48   Gears, revs, and ability of engine to 'pull' - Tooslow

Ah, yours has the supercharger and the turbocharger? Wife's only has the turbo (122bhhp model) but boy is that effective! John Reply to this message | Report message

New Wed 9 Mar 11 10:34   Gears, revs, and ability of engine to 'pull' - Stuartli

>>Wife's only has the turbo (122bhhp model) but boy is that effective!>> Yes, it's a cracking engine. Maximum torque is between 1,500rpm and 4,000rpm. ...and it's supercharged...:-) "Engine: 1,390cc, four cylinders, 16 valves, direct injection, supercharger and turbocharger, 122bhp at 5,000rpm, 148lb ft at 1,500-4,000rpm." Good for 0-60mph in around 9.4 seconds. Last edited by: Stuartli on Wed 9 Mar 11 at 10:35 Reply to this message | Report message