Engine Size vs BHP
Discussion
I hope this is not a stupid question, but I am intrigued by some figures I have been looking at. I am currently looking a two cars, probably boring ones to many on here, but it's to do a job for work and to get the family about.
One is the 1.6 Kia Ceed which has a 133bhp engine and the other is a 1.4 Seat Leon which has a 138bhp engine. Now, I always thought that the larger to cc of the engine, the more power it would have, but it looks to me that the 1.4 Leon has the more powerful engine.
I am after something that will be happy cruising on the motorway, so in the case above, would the two engines be roughly equal, even though one is a 1.4 and the other a 1.6 and I always thought a 1.6 would be more powerful?
One is the 1.6 Kia Ceed which has a 133bhp engine and the other is a 1.4 Seat Leon which has a 138bhp engine. Now, I always thought that the larger to cc of the engine, the more power it would have, but it looks to me that the 1.4 Leon has the more powerful engine.
I am after something that will be happy cruising on the motorway, so in the case above, would the two engines be roughly equal, even though one is a 1.4 and the other a 1.6 and I always thought a 1.6 would be more powerful?
There often can be a correlation between displacement and power, but its not really anything to go by.
Typically car manufacturers used to give an engine line up of various different sizes. More often than not the most powerful was also the largest and most desirable.
If we take VW for example, in the 2000's they made both a 1.6 16v engine and a 1.4 16v. Both were of similar design. The 1.6 developed 100bhp and the 1.4 developed 75bhp, so here what you suggest would apply. However, they also made a 1.8 20v and a 2.0 8v. The 1.8 produced 125bhp and the 2.0 115bhp. This was because the engines were of a complete different design and used different parts. Parts make a lot of difference, which brings me on to the GTI which produced 150bhp thanks to the inclusion of a "turbocharger" forcing a higher quanity of cool air into the engine.
This really is the tip of the iceberg on your question, but hopefully perks your interest
Typically car manufacturers used to give an engine line up of various different sizes. More often than not the most powerful was also the largest and most desirable.
If we take VW for example, in the 2000's they made both a 1.6 16v engine and a 1.4 16v. Both were of similar design. The 1.6 developed 100bhp and the 1.4 developed 75bhp, so here what you suggest would apply. However, they also made a 1.8 20v and a 2.0 8v. The 1.8 produced 125bhp and the 2.0 115bhp. This was because the engines were of a complete different design and used different parts. Parts make a lot of difference, which brings me on to the GTI which produced 150bhp thanks to the inclusion of a "turbocharger" forcing a higher quanity of cool air into the engine.
This really is the tip of the iceberg on your question, but hopefully perks your interest
I should have added that BHP is not the whole story, don't forget torque figures, a more torquey engine can actually be easier and faster to drive than a high revving power house requiring constant gear changes to keep on the power curve.
Generally larger displacement engines will have more torque.
Generally larger displacement engines will have more torque.
Goody13 said:
I hope this is not a stupid question, but I am intrigued by some figures I have been looking at. I am currently looking a two cars, probably boring ones to many on here, but it's to do a job for work and to get the family about.
One is the 1.6 Kia Ceed which has a 133bhp engine and the other is a 1.4 Seat Leon which has a 138bhp engine. Now, I always thought that the larger to cc of the engine, the more power it would have, but it looks to me that the 1.4 Leon has the more powerful engine.
I am after something that will be happy cruising on the motorway, so in the case above, would the two engines be roughly equal, even though one is a 1.4 and the other a 1.6 and I always thought a 1.6 would be more powerful?
How complicated do you want this to be?One is the 1.6 Kia Ceed which has a 133bhp engine and the other is a 1.4 Seat Leon which has a 138bhp engine. Now, I always thought that the larger to cc of the engine, the more power it would have, but it looks to me that the 1.4 Leon has the more powerful engine.
I am after something that will be happy cruising on the motorway, so in the case above, would the two engines be roughly equal, even though one is a 1.4 and the other a 1.6 and I always thought a 1.6 would be more powerful?
In order to produce power, you need combustion, which requires fuel, air and ignition. However, the fuel to air ratio needs to idealy be 14.7/1. So that's 14.7 parts of air to fuel. So in order to make more power, you need more fuel but as you have to keep a 14.7/1 ratio, you need to increase air as well. Therefore you need to increase the size or number of cylinder in which to fill with more air (and then fuel). So the bigger engine has the greater potential for power. That's the basics. You can avoid increasing the size of the engine by compressed the air and therefore getting more air into the cylinder, more fuel and therefore more power. This is done by super/turbocharging. This is all with regards to maximum potential power - there are a whole many variables concerning the potential power of the engine - design, cost, materials used, fuel efficiency, longevity, power-band etc. An engine designed for every day road use is go to require compromises as opposed to a race engine which is designed to run flat out all the time. So power will be different.
With regards to your query, the 1.4 Seat engine is a TSi, that's to say that it has both a supercharger and turbocharger, in order to give a small capacity engine similar characteristics of a larger engine. So the Seat 1.4 TSi would be the equivalent of 1.8 or 2.0 NA engine. The Kia has a 1.6 NA engine. 130bhp/116lbs/ft @ 6k built by Hyundai. The Seat is a VAG unit 123bhp/148lbs/ft @5.6k.
So the Seat has a little less power built more torque and at lower revs. The Kia unit will rev higher and have a touch more power but will need to driven harder. The Seat engine is better (could be remapped too) and I drove one last week and it was fine for mixed use (m-way and b-roads). The Kia motor is less sophisticated and efficient but then it's also simpler, with far less to go wrong.
To add, power (BHP) is a notional figure. That's to say, what you actually measure is the torque of the engine. The power (BHP) is a calculation of torque x revs / 5252.
So for example, the Golf R32 makes 250bhp @ 6250revs, which is very similar to a BMW M3 with the same 3.2l capacity - meaning that the have very similar torque outputs. The difference though is that the M3 will revs to 7500 and therefore the power figure will be greater.
So for example, the Golf R32 makes 250bhp @ 6250revs, which is very similar to a BMW M3 with the same 3.2l capacity - meaning that the have very similar torque outputs. The difference though is that the M3 will revs to 7500 and therefore the power figure will be greater.
TEKNOPUG said:
To add, power (BHP) is a notional figure. That's to say, what you actually measure is the torque of the engine. The power (BHP) is a calculation of torque x revs / 5252.
So for example, the Golf R32 makes 250bhp @ 6250revs, which is very similar to a BMW M3 with the same 3.2l capacity - meaning that the have very similar torque outputs. The difference though is that the M3 will revs to 7500 and therefore the power figure will be greater.
I don't see power is "notional". Its a measure of the engines maximum output - and output is the reason you have an engine in the first placeSo for example, the Golf R32 makes 250bhp @ 6250revs, which is very similar to a BMW M3 with the same 3.2l capacity - meaning that the have very similar torque outputs. The difference though is that the M3 will revs to 7500 and therefore the power figure will be greater.
A waterwheel has masses of torque, but due to its low speed, not much in the way of power.
in your example the M3's additional power isn't notional or a trick of the maths. If you equate torque to lifting a weight the M3 can lift the same weight much faster. It is 'making' more energy and ultimately will make a car go faster/accelerate more. It may be a greater challenge for the driver to be the right gear.
Edited by balls-out on Friday 8th August 14:50
Prawnboy said:
Prawnboy said:
the 1.6 Kia is a diesel too isn't it?
get the SEAT, simple as that.
acctually i see they do a pertrol one......get the SEAT, simple as that.
.....still get the SEAT
I've driven a few Kias and have come away quite impressed. Perfectly good A to B cars. Obviously they don't quite have the imagine of the VAG motor.....
Good grief.
This reminds me of a conversation I had with a rather mentally challenged man who was convinced his Fiat Stilo was much quicker than my car (in every respect) becuase it had a 2 litre engine compared to my 1.8. Now I'm not saying my car was quick by PH standards, but judging it on engine size alone is inaccurate.
This reminds me of a conversation I had with a rather mentally challenged man who was convinced his Fiat Stilo was much quicker than my car (in every respect) becuase it had a 2 litre engine compared to my 1.8. Now I'm not saying my car was quick by PH standards, but judging it on engine size alone is inaccurate.
shalmaneser said:
Prawnboy said:
Prawnboy said:
the 1.6 Kia is a diesel too isn't it?
get the SEAT, simple as that.
acctually i see they do a pertrol one......get the SEAT, simple as that.
.....still get the SEAT
I've driven a few Kias and have come away quite impressed. Perfectly good A to B cars. Obviously they don't quite have the imagine of the VAG motor.....
I'm not a lover of VAG, (well not that sort), but the SEAT is a wee bit more PH. It's the one i would choose out of the two.
but if i wanted a bog standard car of that size i would get a focus to be fair.
shalmaneser said:
Obviously they don't quite have the imagine of the VAG motor.....
quite.I have driven an diesel FR and was hugely impressed by the handling and feedback through the wheel by modern diesel standards and the interior was rather good, generally a nice place to be (far better than the 118d which I guess is vaguely analogous?). Satnav was utter pants though.
Can't comment on Kias but only heard good things about them.
Aanyway, what Op might like to read, if he's not a troll, is this, mainly the "Highest specific engine output (power/unit displacement)" section, although the engine power to weight section above is rather interesting.
Also, inertial supercharging.
balls-out said:
I don't see power is "notional". Its a measure of the engines maximum output - and output is the reason you have an engine in the first place
A waterwheel has masses of torque, but due to its low speed, not much in the way of power.
in your example the M3's additional power isn't notional or a trick of the maths. If you equate torque to lifting a weight the M3 can lift the same weight much faster. It is 'making' more energy and ultimately will make a car go faster/accelerate more. It may be a greater challenge for the driver to be the right gear.
It is notional purely because it doesn't exist. You can't measure horse-power. You can measure torque and you can measure revs. You can then do a calculation using those to figures to produce a number to describe the amount of work the engine does. You could take your shoe size and multiply it by the number of tiles on your roof to determine a value for X. X doesn't actually exist though.A waterwheel has masses of torque, but due to its low speed, not much in the way of power.
in your example the M3's additional power isn't notional or a trick of the maths. If you equate torque to lifting a weight the M3 can lift the same weight much faster. It is 'making' more energy and ultimately will make a car go faster/accelerate more. It may be a greater challenge for the driver to be the right gear.
Edited by balls-out on Friday 8th August 14:50
Using your waterwheel example "not much in the way of power" if purely subjective. If an engine has lower revs but high torque, it can still produce a lot of power. A Rolls Royce Merlin engine may only run at 3000rpm but they still produce 1,600bhp
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