Just a heads up, the 1.5lt engine is showing on the Skoda configurator. It's £300 more than the 1.4lt.

What are its plus points? The trend was downsizing towards more thermally efficient engines. Does the larger engine with, cylinder deactivation, truly give better mpg and lower emissions?

1 hour ago, gregoir said:

What are its plus points? The trend was downsizing towards more thermally efficient engines. Does the larger engine with, cylinder deactivation, truly give better mpg and lower emissions?

My understanding is it's a direct replacement for the 1.4 which I would expect to disappear off the lists fairly quickly.

5 hours ago, gregoir said:

What are its plus points? The trend was downsizing towards more thermally efficient engines. Does the larger engine with, cylinder deactivation, truly give better mpg and lower emissions?

Downsized engines were designed to meet and shine in the current undemanding consumption and emission tests but the proposed new 'real world' tests would have shown deficiencies when asked to perform in a more demanding environment.

A number of manufacturers have said that downsizing is no longer viable in the new world order.

The new 1.5 is more advanced but in its first iteration seems to have similar performance and consumption to the 1.4tsi (ACT version) but is likely to have far better emissions and far better development potential going forward.

Edited 8 July, 20178 yr by Gerrycan

Manual only too, no DSG at the moment.

On 7/7/2017 at 23:51, fergiet said:

Just a heads up, the 1.5lt engine is showing on the Skoda configurator. It's £300 more than the 1.4lt.

 

I wonder if it has a GPF?

 

It was also originally supposed to have a variable vane turbo

Edited 9 July, 20178 yr by bigjohn

Don't know about the GPF although I believe it is needed for Euro7.

Variable vane turbo is the single biggest innovation for this new engine only having been available on a Porsche petrol engine previously. This is the first mass produced petrol application although diesels have had it for sometime. Lubrication challenges on petrol prevented earlier introduction, I read somewhere.

I'm not sure when it will be coming to Australia as it is not available on the Golf 7.5 and probably something to do with our lower emission standards (relatively recent introduction of Euro5) and much higher sulphur levels in our fuel.

Whats GPF????

DPF is Diesel Particulate Filter so presume GPF is Gasoline Particulate Filter but could be PPF as well I suppose?

Same working principles but I assume the petrol particles would be smaller so trapping them would be the challenge although the burn off would probably be less frequent.

1 hour ago, Gerrycan said:

DPF is Diesel Particulate Filter so presume GPF is Gasoline Particulate Filter but could be PPF as well I suppose?

Same working principles but I assume the petrol particles would be smaller so trapping them would be the challenge although the burn off would probably be less frequent.

VAG said publicly last year(?) that they will be introducing GPF onto all their petrol/gasoline models.

I would like to think this had been subject to rigorous and lengthy prototype testing and development prior to introduction. 

5 hours ago, Gerrycan said:

Don't know about the GPF although I believe it is needed for Euro7.

Variable vane turbo is the single biggest innovation for this new engine only having been available on a Porsche petrol engine previously. This is the first mass produced petrol application although diesels have had it for sometime. Lubrication challenges on petrol prevented earlier introduction, I read somewhere.

I'm not sure when it will be coming to Australia as it is not available on the Golf 7.5 and probably something to do with our lower emission standards (relatively recent introduction of Euro5) and much higher sulphur levels in our fuel.

 

On some petrol engines a Gasoline Particulate Filter is required for Euro 6C due to particulate production by later efficient direct injection petrol engines. One earlier port injection engines this wasn't a problem

 

In Europe/UK the 1.8/2.0tsi now has both port and direct injection

 

I'll be avoiding early implementations of the GPF and petrol variable vane turbo

 

[EDIT] The GPF will be somewhat simpler than a DPF implementation due to the higher combustion temperatures with petrol - and thus will only use passive regen

 

Edited 9 July, 20178 yr by bigjohn

15 hours ago, bigjohn said:

higher combustion temperatures with petrol

 

 

What? Doesn't sound right to me. Diesel burners have approx 2x the compression of Petrol. 

8 hours ago, TDIum said:

 

What? Doesn't sound right to me. Diesel burners have approx 2x the compression of Petrol. 

 

It's to do with the burn temperature of the fuel not cylinder compression

 

http://www.lubricants.total.com/news/new-gasoline-particulate-filters-gpf.html

 

9 hours ago, TDIum said:

 

What? Doesn't sound right to me. Diesel burners have approx 2x the compression of Petrol. 

Petrol does indeed burn hotter then diesel, but at the same time is less thermally effiecent then diesel; has why diesel engine used to do almost double the mpg then petrol did. the only way that compression comes into play is how the fuel is ignited, diesel uses compression to ignite rather then a spark ; hence why it is greater on diesel engines.

 

Modern petrol engines run at about 10.5 to 1 ratio and diesel runs it about 18 to 1 ratio; thats also why why diesel engines are inherently tougher the petrol as well.

1 hour ago, Ju1ian1001 said:

 has why diesel engine used to do almost double the mpg then petrol did

 

 

My first diesel was a 1990 Astra MKII "non turbo" diesel which was mega slow - this did about 43mpg

A previous company car 1989 Astra MKII 1.3 petrol (rather nippy in it's day) - did about 39mpg on the same long distnce driving

 

I also had a 1990 Passat 1.6td diesel that did about 45mpg

The 2001 Octavia 1.4 16v that replaced it did about 43-4mpg (and still does on a run)

 

I've always done lots of long distance journeys/long commutes though. If you just drove around town diesel was much more economical (although these days that doesn't suit a DPF!)

 

 

 

Edited 10 July, 20178 yr by bigjohn

13 hours ago, TDIum said:

 

What? Doesn't sound right to me. Diesel burners have approx 2x the compression of Petrol. 

The difference is not quite as much as that these days and the Mazda SkyActive engines are very interesting as the diesel ratios are down to 15:1 and petrols are up to 14:1.

14 hours ago, bigjohn said:

 

It's to do with the burn temperature of the fuel not cylinder compression

 

http://www.lubricants.total.com/news/new-gasoline-particulate-filters-gpf.html

 

 

The article talks about higher exhaust gas temperatures. 

 

I was always told diesels ran hotter meaning less friction, and that was why diesels engines did not wear out as quick as petrol engines.

47 minutes ago, POWYSWALES said:

I was always told diesels ran hotter meaning less friction, and that was why diesels engines did not wear out as quick as petrol engines.

 

Not quite true.

 

Diesel engines were/are slightly over engineered to cope with the higher loads imposed with compression ignition also diesel fuel has lubricating qualities that petrol does not.

The next step in reducing pollution from petrol engines then. Lets hope GPF has fewer problems than DPF. I switched to petrol to avoid those as my mileage is now lower.

But will the real world mpg be as good as the current 1.4TSI which is superb on long runs. 

4 hours ago, gregoir said:

 

But will the real world mpg be as good as the current 1.4TSI which is superb on long runs. 

 

That's what I'm wondering. Even my big tsi bus can better 50mpg if you take it steady (which I don't!)

 

I'm keeping an eye on hybrid technoogies (very impressed with the way a friend Auris hybrid drives) - impressed with Toyota/Lexus hybrid running gear, but all the Toyota hybrids seem to be pug ugly and somewhat challenged re luggage space