How can a 1.2 engine outperform a 1.6 of the same model?

How can a 1.2 engine outperform a 1.6 of the same model?

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ScotHill

Original Poster:

3,529 posts

116 months

Thursday 23rd November 2023
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Tried a 1.6 manual petrol car, very reluctant in first gear, picked up a bit in second but didn't get remotely exciting at any point.

From reviews the 1.2TCe outperforms it, even though the engine is smaller. What's going on there, would it have extra tech to make the most of a smaller engine, does TCe stand for something fancy that I've never heard of?

Master Bean

4,012 posts

127 months

Thursday 23rd November 2023
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Turbo.

ScotHill

Original Poster:

3,529 posts

116 months

Thursday 23rd November 2023
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Master Bean said:
Turbo.
Is there a decent short overview video of what a turbo does on a petrol car, as my understanding of them is similar to the afterburners on a jet fighter, or that wee snail that got to go really fast in that animated film.

anonymous-user

61 months

Thursday 23rd November 2023
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Turbo Control Efficiency, I am assuming this is a Renault?

I have the 1.4 TCE engine in my car and it is excellent, It has similar low down torque to my old 1.5 DCi and feels way faster. On paper it has way better figures than the 1.6, it's faster and produces more low down torque, plus peak power is produced at lower revs.

Truckosaurus

12,047 posts

291 months

Thursday 23rd November 2023
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If the car in question is a Dacia Duster then there is also gearing to consider as some (all?) of them have extra low first gears to give it some off road capability.

Also the 1.2 has 10-20bhp more than the 1.6 depending on version (plus a load more low down torque)

As to how a turbo works - I'm sure the is a wikipedia page with pictures - but basically the exhaust gas spins the turbo which compresses the intake air so you can get more air into the cylinder and therefore more fuel and power.

SkodaIan

783 posts

92 months

Thursday 23rd November 2023
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ScotHill said:
Is there a decent short overview video of what a turbo does on a petrol car, as my understanding of them is similar to the afterburners on a jet fighter, or that wee snail that got to go really fast in that animated film.
There are loads - just search for "how a turbocharger works" into the search of a well known video site.

Fundamentally, the turbo forces air in which then makes the fuel burn faster...

ScotHill

Original Poster:

3,529 posts

116 months

Thursday 23rd November 2023
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Ah so turbo is related to turbine, that makes sense now.

It is a Renault and I'm trying the 1.2 over the weekend, will see how much difference it makes. I thought there might have been something wrong with the 1.6 we drove but reading up it's just a bit of a crap car. smile

samoht

6,290 posts

153 months

Thursday 23rd November 2023
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The engine's power is made by burning fuel in air.

Fuel is liquid so doesn't take up much room, air is a gas so takes up most of the space in the engine.

So the engine power is limited by how much air you can fit in it.

If you want more power you can either have a bigger engine, or you can squash the air to fit more in.

A turbo is a pump which feeds the engine with compressed air, thus fitting more air in the cylinder, thus making more power.

You might find a turbo compresses the air to half the size, which means that a 1.2 engine would feel like a 2.4 in terms of the power it gives.

At the extreme, F1 cars only have a 1.6 L turbo engine and are obviously extremely powerful and fast.

anonymous-user

61 months

Thursday 23rd November 2023
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samoht said:
The engine's power is made by burning fuel in air.
The perfect mix of air and fuel is 14.7:1, this is called The stoichiometric mixture for a petrol engine. This is 14.7:1 to weight, so effectively 14.7 grams of air to 1 gram of petrol.

As the poster above states, the only way to increase power is to have a bigger engine or compress the air so you can squeeze more air (and hence fuel) into the engine. A turbocharger uses the gas from the exhaust to run a compressor which compresses the air and allows more air and fuel into the engine to produce more power.

Boyles law states that if you compress a gas the temperature increase, hence why most turbo charged engines have an inter cooler to cool the compressed air before it is fed back into the engine.

AAaltered

1,090 posts

187 months

Wednesday 29th November 2023
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The Citroen Cactus motors are 1.2 petrol (turbo) and the 1.6HDI (FORD) diesel (turbo) with the 1.2 being significantly faster than the 1.6.