Engine size effects on petrol

[Xt500]

Every diesel will be more 'torquey', not necessarily more powerful. Mileage depends on tank capacity, so that doesn't give a good indication of fuel efficiency as some tanks are bigger than others. I disagree about the brakes - that's obviously not true if you look at the official stopping distances. Smaller cars do not eat fuel any more than larger ones, obviously. Hard work? Yes, they can be hard work sometimes, but parking can be so much easier!

 

Mileage depends on tank capacity? Man its all education here!

 

Cant even be bothered with the rest.

[liam_p91]

I'm looking at astras for around 3k torn wether to go for a 1.4, 1.6 or 1.7tdci. I don't go very far tbh work in meadowhall and go I uni in town

 

---------- Post added 01-09-2014 at 09:05 ----------

 

Who's 19 lol I'm 23 and have a kid

[Xt500]

I'm looking at astras for around 3k torn wether to go for a 1.4, 1.6 or 1.7tdci. I don't go very far tbh work in meadowhall and go I uni in town

 

---------- Post added 01-09-2014 at 09:05 ----------

 

Who's 19 lol I'm 23 and have a kid

 

why a vauxhall,their diesels are crap.

[neeeeeeeeeek]

You don't need a diesel if you just do short local trips.

[truman]

They cost more too & don't save any fuel on short trips, so you'd need to do a lot of driving to ever see any saving. Under 40mpg is pretty poor to be fair, I get that usually driving round town in a 1.5 petrol.

 

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I have a focus 1.6 tdci..my overall average since I've had it (nearly 3 years) is 54mpg..

[drummond]

I drove a Mk5 1.7 CDTI Astra and it was really horrid to drive, the engine was totally gutless when the turbo wasn't on song, the interior felt cheap and nasty and the ride in general was rubbish.

The 1.4 was pretty crap as well come to think of it.

 

It's no use claiming a deisel is more economical than a petrol as they run on different fuel. My mate has a gas conversion. It uses about 20% more LPG than it does running petrol, but LPG isn't petrol. It is also around 1/2 the price so economy is how much it costs to run.

At the moment the trend is away from oil burners and towards small petrol engines with high output turbos. They give good mileage and low CO2. It is clear that deisel is about to get clobbered because of particulates. So they won't be cheap to run much longer.

In 5/10 years most new cars will be powered by tiny turbo petrol engines powering KERS type motors. I'll hang back on replacing my supercharged petrol until they come along.

In the meantime take a look at BMW I8 & I3 if you want to see the future. The future is here today.

[Obelix]

Can't be bothered reading it. I get the just. ... Two people running along the motorway. One with long legs one with short legs. Short leg is working two times as hard compared to the long leg Dood. Big engine on a motorway will not break a sweat. The pistons move slow and steady. Less fuel. The short leg ( small car) Pistons going up an down like a loony , More fuel. >>> if you drive to the local shops, go small, If you do motorway go big!. >> Big will use more fuel going to the shops, And small will use more fuel on motorway!.

 

---------- Post added 01-09-2014 at 02:05 ----------

 

For a good compromise get hold of a 1.7 turbo diesel.

 

Not really. A small fast running engine is more efficient than a large engine. Most engines are at peak efficiency at close to maximum power - that's why a lot of the large V8 engine in the US now switch off half the cylinders when cruising in order to run the remainders are a higher power setting, saving fuel.

[Xt500]

It's no use claiming a deisel is more economical than a petrol as they run on different fuel. My mate has a gas conversion. It uses about 20% more LPG than it does running petrol, but LPG isn't petrol. It is also around 1/2 the price so economy is how much it costs to run.

At the moment the trend is away from oil burners and towards small petrol engines with high output turbos. They give good mileage and low CO2. It is clear that deisel is about to get clobbered because of particulates. So they won't be cheap to run much longer.

In 5/10 years most new cars will be powered by tiny turbo petrol engines powering KERS type motors. I'll hang back on replacing my supercharged petrol until they come along.

In the meantime take a look at BMW I8 & I3 if you want to see the future. The future is here today.

 

What are you on about?

 

The thread isnt about whats going to happen in 10 years time its about how the OP is going to get to work next week!!

Most petrols cant match a diesel on MPG,power,or effort to drive.Further to that diesels are far far more reliable and cost less to service.

Of course good diesels cost more and for very good reason,already listed!

[drummond]

What are you on about?

 

The thread isnt about whats going to happen in 10 years time its about how the OP is going to get to work next week!!

Most petrols cant match a diesel on MPG,power,or effort to drive.Further to that diesels are far far more reliable and cost less to service.

Of course good diesels cost more and for very good reason,already listed!

 

How odd. I always assumed people bought cars to use in the future not just for one day. Just imagine buying a deisel car next week and finding the tax band and fuel tax went through the roof in the next budget.

[Obelix]

It's no use claiming a deisel is more economical than a petrol as they run on different fuel

 

But you can make that comparison. You measure the energy input from the chemical energy of the fuel, and look at the output energy delivery. From that you will find that a Diesel cycle is considerably more efficient than an Otto cycle engine. The reasons for this are well understood and come from the limitations of the Carnot cycle and how you exploit that to gain maximum efficiency.