Engine Power

[CyberCynth]

I have a question for you techies!

For the benefit of the uninitiated, what is the difference between BHP and engine size? I ask the question because I saw a Skoda Octavia for sale which I was tempted by. The engine size is 1.4 and the BHP is 75. Now, my little Skoda Fabia is only a 1.2 but 105 BHP. So would there be any point in changing to a car with a bigger engine, with less BHP?

One person I asked said that because my 1.2 has a turbo, it would probably be more powerful than a 1.4 in a conventional engine. Is that right? I understand a little about the internal combustion engine, but the more complex they become the harder it is for my none-technical brain to take it all in. Where turbos fit into the grand scheme of things is completely beyond me......

 

[WoodlandsCamper]

Good question, Cynth.
Stand by to be blinded by science. (but not by me).

 

[CyberCynth]

Shucks, W.C., saw your reply and thought you'd got the answer to my conundrum.

Ok, I'm waiting.........

 

[Sproket]

Cynth you can

Watch how they work :lol:

 

[seth1]

Basically in todays world,the general belief is forget about engine size and look at the power and torque output.Many people believe size is irrelavant because at the end of the day lets say 150hp is 150hp whether it comes out of a 1.4 or a 2.0 its still 150hp.
But what people forget is the 1.4 may produce 150hp but were does the power curve start and end,it is very likely to be like a light switch,either on or off.
As a perfect example i looked at possible a new car recently,A 2.1 two stage turbocharged diesel(two turbos of different sizes)badged up as 250hp as to compete with the 3litre segment with similar power.Yes it does make similar power but for all of 100rpm.complete waste of time.
My opinion is the larger the engine the better.

 

[CyberCynth]

Wow! Thanks for that link, Sproket. If I watch it about another 10 times it might just sink in! Seriously though, it just amazes me how far technology has advanced in terms of the internal combustion engine. I don't know how these folk work it all out. Clever stuff.

 

[Thingy]

Im with Seth on that one, I prefer the bigger engine even if the torque and bhp are the same. Another byproduct of the bigger engine can often increase the kerbweight of the vehicle, which as you know for caravanners is like ambrosia.

Dont forget also two identical engines with the same bhp would work differently in different cars, i.e power to weight ratio, gearing length and ratios and a myriad of other small points. A bigger engine in the same weight of car, especially a heavy car will often give you better fuel economy, particualry whist towing.

 

[WoodlandsCamper]

Good question, Cynth.
Stand by to be blinded by science. (but not by me).

Are you glad you asked the question now, Cynth??

Have you got the answers you wanted? :S

 

[CyberCynth]

Good question, Cynth.
Stand by to be blinded by science. (but not by me).

Are you glad you asked the question now, Cynth??

Have you got the answers you wanted? :S

Question 1: Um.... Not sure.
Question 2: Um.... Not sure.

However someone told me yesterday they'd test driven, against their better judgement, a 1.4 TSi Octavia, when they'd actually asked for a test drive in a 2L. DSi. They were so impressed with the power offered by the 1.4 TSi, they ordered a new one there and then! That didn't tell me anything about the technicalities of engine size versus BHP, but it told me all I needed to know about my own situation; that is, I shall be happy to stick with what I've got now, and will not worry about buying a car with a bigger engine!

Thank you all for your input, anyway!

 

[ProfJohnL]

Hello Cynthia,

Your post could have opened up a massive can of worms, I'm frankly surprised that you had so few answers. And none of then actually answered your questions.

BHP stands for Brake Horse Power and engine size simply describes the volume of the cylinders in the engine. Before such wide spread use of turbocharges and other performance enhancements it was generally accepted that a bigger engine would produce more power, but these days manufacturers are making smaller engines to save weight and to enhance their green credentials, but getting them to produce much more power.

Most manufactures produce a small number of engine sizes, and you can often find the same sized engine fitted in different models with different power outputs. Volkswagen/Audi Group play this game a lot, they produced basically the same engine with power outputs of 90, 110, 140 and 170 BHP. They produce the differences by employing Features such as Superchargers, Turbochargers, engine management/fuel injection, lean burn techniques not forgetting the basic fuels Petrol and diesel.

As you have described they produce a 1.2L engine with peak power of 105BHP but a larger 1.4L engine with only 75BHP.

But as Seth points out just comparing the BHP does not tell you everything you may need to know about a car, especially if you are thinking of towing. It is still generally true that diesels are better for towing, because of another engine characteristic called "Torque". But some larger petrol engines can also provide plenty of torque so you see its a vast subject, and how it all fits together today, may not be true tomorrow. Things are changing quite quickly in the world of engines.

Who knows, Formula 1 may go over to diesel or Steam with the next set of rule changes!

 

[colin-yorkshire]

Who knows, Formula 1 may go over to diesel or Steam with the next set of rule changes!

nah!!! all Electric, John steam and diesel use fossil fuels,

 

[WoodlandsCamper]

nah!!! all Electric, John steam and diesel use fossil fuels,

And what is used to produce the electric?? Fossil fuels??

 

[ProfJohnL]

Heat for Steam can be generated from wood, and diesels can run on Bio oils.

 

[Raywood]

If you intend to tow then torque is what you should look at and the lower in the rev range the better.

 

[seth1]

Audi have been running V10 diesels for along time now in Lemans and winning.But i dont think a diesel would be suited to formula 1 due to the limit on engine sizeing.

 

[CyberCynth]

ProfJohnL:

Thanks for your informative post.

More talk about torque; someone once described torque to me as an engine which has longer connecting rods than a sporty engine, and therefore better pulling power. Having just looked up the figures for my little Skoda, the max torque is 175nm /1,500 - 4,100 rpm. I'm not sure how that would compare to the Octavia's 1.4TSi model I looked at last week. (or indeed, how it would compare with a diesel engine of the same size). The Skoda dealer to whom I spoke seemed to think there would be little advantage in changing my car. Especially as the tax band was higher in the 1.4 (For that year's model, at least) This is the first time I have been talked OUT of changing my car, by a salesman! Apparently once Skoda started to fit turbos to the 1.2 TSi, they stopped producing the 1.6 engine, as the power output was the same in the smaller engine! As you, and others have said, John, technology moves on so fast these days, who knows what wonders will be available to us next year?

Electric cars? yes, I agree they're not as green as we like to think, when they reach the end of their useful lives, they are very 'dirty' things to dispose of, and production of electricity is also, as has already been pointed out, not actually very green!

Did anyone watch the series on T.V. called 'Water, a Dirty Business'? In one episode, tonnes of dried fat had clogged up a sewer, It was taken away by a company turning fat into biofuel. I can't understand why chip shops still tip their fat down the drain, when they could get rid of it to biofuel converters. Too lazy?

 

[ProfJohnL]

Audi have been running V10 diesels for along time now in Lemans and winning.But i dont think a diesel would be suited to formula 1 due to the limit on engine sizeing.

I don't see that is a problem, The F1 rules were changed recently to limit engine size,fuel load, fuel consumption, etc etc etc. So its perfectly within the FIA's remit to make changes, to accommodate diesel power trains.

 

[DeliDave_]

They are supposed to fit grease traps now anyway,I've unblocked sinks even on Xmas day with blocked fat

"legislation and guidance

Water authorities are no longer allowing untreated waste to be flushed down the drains. Employ Filtra-Trap in your premises for a cost efficient environmentaly friendly solution to waste management.

Revised Building Regulation requires all new builds and refurbishments of hot food premises to have an effective means of grease removal on site. They are required on all sites that prepare hot food for the public or staff"