Downsizing of engines soon to be reversed

[Wakey]

Interesting article here

 

In a nutshell the development that went in to small capacity forced induction engines seems to have reached its limits and now manufacturers are increasing engine capacity to meet new emissions laws.

 

 

[moley]

Interesting article that exposes the fact that real world figures for emissions of most makes are way above the lab figures. In a roundabout way we should thank VW for getting caught out with their 'cheat' software for highlighting the problem.

Fiat, Renault and Opel have the worse emission figures on the Euro 6 engines, lets see what the EU does about this....

 

Edit: this should really be in general car chat.

Edited 16 October, 2016 by moley

[threadbear]

Interesting article. I always did wonder how a 1.0 ;litre engine would cope with a car the size of a Mondeo or Golf. Well it looks like the engines have to work like hell to get the performance and emissions in the real world suffer as a consequence. 

 

Maybe Mazda using a modern 2.0 litre normally aspirated petrol engine have the right idea? 

 

Whatever the answer, this continual change in direction in development of the internal combustion engine does mean that its days are really numbered? 

[ColinD]

It's got a few years yet, maybe 10.

 

Outside of major urban areas, probably for 30+.

 

A 1.0 mondeo would work fine if we were all passengers and it didn't have to make 70 before the 100yard marker, or have hills. 

[Ootohere]

This 3 cylinder engine that Mahle are developing fitted to a Golf GTI looks interesting.

http://carmagazine.co.uk/car-reviews/volkswagen/vw-golf-gti-by-mahle-12-litre-3cyl-prototype-2016-review

E-Superchargers just like the VW Group have been developing in their Audi factories and have production ready for petrols and diesels.

 

 

Perfect for Taxi / Private hire cars in cities then, like a 1.0TSI Octavia.

Edited 17 October, 2016 by Offski

[KenONeill]

Why am I not surprised? Have I not always said that what I want is good mid-range and not pretty much academic top end?

[RampantBadger]

Infiniti (i.e. Nissan) believe that varying the engine capacity is the way forward.

 

http://arstechnica.com/cars/2016/08/inifiniti-will-debut-a-variable-compression-ratio-engine-in-september/

 

that way you get the best of both worlds larger capacity for power when accelerating but smaller capacity for cruising for efficiency, add in cylinder deactivation and an electric assist variable vane turbo system and you are on to a real winner!

[Aspman]

I always got the feeling that these low capacity turbo engines were good at lab tests and not an awful lot else.

 

Drove a 1.2T in a Qashqai and it was ok as long as you stayed within it's performance bands, outside of that it was useless. MPG was also mediocre.

 

It was stupid that I could get better mpg figures in an Octy VRS TFSI (not even the TSI) than it.

 

I've found that with decent driving uneconomical cars are generally more economical than you'd think and Vice versa.

[PetrolDave]

Anyone remember the engine developed by Oribtal in Australia in the late 1980's/early 1990's?

 

It was a 3 cylinder two stroke which used the crankcase as a built-in supercharger. I drove a prototype (never released for sale) Ford Fiesta at the Dunton Research Centre which had one fitted, it was amazing with massive torque (you could do a standing start easily in third gear) and revved beautifully. But because it was a two stroke (self oiling so you didn't have to add two stroke oil when filling up!) it couldn't meet even EU3 emissions regulations so it got killed off.

[Geek42]

Infiniti (i.e. Nissan) believe that varying the engine capacity is the way forward.

 

http://arstechnica.com/cars/2016/08/inifiniti-will-debut-a-variable-compression-ratio-engine-in-september/

 

that way you get the best of both worlds larger capacity for power when accelerating but smaller capacity for cruising for efficiency, add in cylinder deactivation and an electric assist variable vane turbo system and you are on to a real winner!

 

This article is talking about different compression ratios, not capacities. I believe that high compression ratio is one of the advancements in formula 1 that had allowed them to increase the thermal efficiency (and where Mercedes initially had a huge advantage over the rest). I think I read that they pre-ignite some of the fuel in a separate chamber and inject it already burning into the main mix to allow more even ignition at higher compression, although they obviously use different fuel to a road car as well!

 

Regarding electric superchargers, they seem to be a good idea and I saw a demo of something similar (on a rep mobile rather than a GTI) 5 or 6 years ago, along with an energy recovery unit to power it for "free". The company sold the electric supercharger business to a major Tier 1 automotive supplier, so I'm surprised that we haven't seen much e-charging yet, although I suppose automotive design cycles can be pretty long.

[Geek42]

I've found that with decent driving uneconomical cars are generally more economical than you'd think and Vice versa.

 

Our right feet are definitely the major contributor!

 

I had a 1.6TDCI Focus which I became convinced was better than the 2.0 for fuel efficiency at low speed, but at 80mph there was little difference, and I wished I'd gone for the extra capacity.

 

That said, I find my 1.4TSi to be hugely impressive, and in the real world I get performance that would have been considered hot hatch territory 15-20 years ago, with efficiency that would have been diesel territory back then. The official figures are definitely fiction, but there have also been very real improvements.

[RampantBadger]

This article is talking about different compression ratios, not capacities. I believe that high compression ratio is one of the advancements in formula 1 that had allowed them to increase the thermal efficiency (and where Mercedes initially had a huge advantage over the rest). I think I read that they pre-ignite some of the fuel in a separate chamber and inject it already burning into the main mix to allow more even ignition at higher compression, although they obviously use different fuel to a road car as well!

 

Regarding electric superchargers, they seem to be a good idea and I saw a demo of something similar (on a rep mobile rather than a GTI) 5 or 6 years ago, along with an energy recovery unit to power it for "free". The company sold the electric supercharger business to a major Tier 1 automotive supplier, so I'm surprised that we haven't seen much e-charging yet, although I suppose automotive design cycles can be pretty long.

the way that the compression ratios are adjusted is via a cam which changes the crank profile, it adjusts the compression ratio by changing the swept capacity of the engine.

 

as for the electric assist turbo, they are different to the e-superchargers. its a turbo with an electric motor attached to the shaft. It allows the turbo to be spooled up by the motor providing positive boost pressure at lower revs (i.e. in the lag zone), once the gas flow is fast enough to drive the turbo the motor switches to a electrically brake the shaft to keep it at the optimal speed eliminating the need for a wastegate and regenerating power into the system. F1 are using a similar system on the engines this year.

https://en.wikipedia.org/wiki/Hybrid_turbocharger

[Breezy_Pete]

^ Fascinating stuff, cheers.

[skomaz]

Saab were researching and developing variable capacity engines before they went bust - worked on a flexible block IIRC that could adjust stroke on the fly...

 

https://en.wikipedia.org/wiki/Saab_Variable_Compression_engine

[Geek42]

the way that the compression ratios are adjusted is via a cam which changes the crank profile, it adjusts the compression ratio by changing the swept capacity of the engine.

 

OK, we're getting beyond the realms of my knowledge, but are you suggesting that the piston travel is limited at the bottom instead of (or as well as) at the top? (that wasn't initially how I read the article). Would make sense I guess, if you can implement it properly it might be more effective than cylinder deactivation.

 

Regarding the e-turbo, the thing I saw 5-6 years ago was two separate blocks, one electric powered charger and one gas powered recovery unit, which in theory could have been fitted together or individually. The thing you describe is more integrated and on face value looks smarter, I guess in 5-6 years I should expect some advancement!

[RampantBadger]

OK, we're getting beyond the realms of my knowledge, but are you suggesting that the piston travel is limited at the bottom instead of (or as well as) at the top? (that wasn't initially how I read the article). Would make sense I guess, if you can implement it properly it might be more effective than cylinder deactivation.

Yep that's right, by changing the crank profile at the bottom you change where the piston finishes at the top of the stroke. Its all damned complicated to manufacture but very very clever.

[KenONeill]

Regarding electric superchargers, they seem to be a good idea and I saw a demo of something similar (on a rep mobile rather than a GTI) 5 or 6 years ago, along with an energy recovery unit to power it for "free". The company sold the electric supercharger business to a major Tier 1 automotive supplier, so I'm surprised that we haven't seen much e-charging yet, although I suppose automotive design cycles can be pretty long.

Or maybe it's because electric superchargers (aka fan-chargers) are so much snake oil?

A conventional mechanical drive supercharger (or an exhaust driven turbo-supercharger) takes something like 10bhp (minimum absorption at peak power revs) to 10% of engine power. For a 100bhp engine, that's 10bhp either way, and converting this to SI means you need about 15kW to run the charger motor.

[whitep]

I have been saying this for ages, bigger engines are just as economical as smaller engines. Whenever I have gone from my big engine cars to a courtesy car or hire car with a small engine, I use more fuel!

 

A colleague of mine here has a new Jaguar V8 5 litre petrol 520BHP (I think). Its sitting at 36MPG... now tell me thats bad! My old diesel VRS Octavia barely beat that! And we do the same mileage.

[Ootohere]

So the elephant in the room that sometimes gets attention and then is forgotten is size and weight.

 

We got all the story on engines the size of a A4 sheet of paper, we even get the story on an Audi A4 being lighter.

But passenger cars are often big and often heavy and the engines are heavy and the running gear is unless the manufacture is selling a premium car, 

and often they are big.

 

So a bigger capacity engine does not really need to be heavy, or all that heavy.

The EV's are heavy right now with the battery packs.

 

Small capacity engines can be fuel efficient and have low emissions when the vehicle is the right weight for the size and the passengers and luggage needed to be carried.

Lets see just how much more power and energy is required to make up for the power / energy wasted to make carbon fuel burning vehicles less polluting.

 

Maybe the Vehicle manufacturers can get on with 'adding lightness' and not just by no spare wheel or leather as standard, but add as an option.

Or get on with the testing cars and publishing the figures with them at the Max Gross weight / Revenue weight if they have lots of seats fill then and the boot and then give the MPG & Emissions.

 

If people need or want a vehicle to tow with, then have the vehicles tested at the Max Gross weight towing and then the buyers will know as will the governments 

for miles charging, road tolls or what ever.

Or the UK can just get back to put the TAX & Duty on fuels and not on the vehicles.

 

PS

Are we finished with Wan_kel's for ever, or might VW think that is the future?

Edited 17 October, 2016 by Offski

[VWD]

 

Fiat, Renault and Opel have the worse emission figures on the Euro 6 engines, lets see what the EU does about this....

 

 

Do- EU only does anything when FORCED to -

[logiclee]

Or maybe it's because electric superchargers (aka fan-chargers) are so much snake oil?

A conventional mechanical drive supercharger (or an exhaust driven turbo-supercharger) takes something like 10bhp (minimum absorption at peak power revs) to 10% of engine power. For a 100bhp engine, that's 10bhp either way, and converting this to SI means you need about 15kW to run the charger motor.

 

Some VAG models already have electrically driven compressors and 48V electrics, to lower the current.

 

And that's before we look at the MGU-H on F1 cars.

 

Not so much snake oil but possible future tech?

 

Lee

[FlyingGecko]

Anyone remember the engine developed by Oribtal in Australia in the late 1980's/early 1990's?

 

It was a 3 cylinder two stroke which used the crankcase as a built-in supercharger. I drove a prototype (never released for sale) Ford Fiesta at the Dunton Research Centre which had one fitted, it was amazing with massive torque (you could do a standing start easily in third gear) and revved beautifully. But because it was a two stroke (self oiling so you didn't have to add two stroke oil when filling up!) it couldn't meet even EU3 emissions regulations so it got killed off.

 

 

Yep. CAR magazine frequently ran articles during the life of the Orbital. Very interesting too.

 

 

 

(I'm sure I posted this reply around 11.20 this morning.)

[ScotsDave]

Interesting article. I always did wonder how a 1.0 ;litre engine would cope with a car the size of a Mondeo or Golf. Well it looks like the engines have to work like hell to get the performance and emissions in the real world suffer as a consequence. 

 

 

And if they have to "work like hell" then life expectancy will decrease. I've heard of Fiesta EcoBoosts getting new engines at 4 years old. It wasn't a one-off either - the dealer had 4 in at once waiting on new engines.

Edited 17 October, 2016 by ScotsDave

[Aspman]

And if they have to "work like hell" then life expectancy will decrease. I've heard of Fiesta EcoBoosts getting new engines at 4 years old. It wasn't a one-off either - the dealer had 4 in at once waiting on new engines.

 

SWMBO had a Tigra with a 1.4 that was woefully underpowered when I had the VRS. Got ragged everyday of it's life.

At 80k it was an oil drinking. smoking, whimpering wreck of a car struggling to get through the emissions test. My VRS was running like new at 80k with emissions too low to read and getting 10-15mpg more than the tigra (yup Tigra was down to mid 20s).

 

If these little engines are powerful enough they probably will last ok, but the turbos must be on full time. They can't last 10yr surely?

Edited 17 October, 2016 by Aspman

[KenONeill]

Some VAG models already have electrically driven compressors and 48V electrics, to lower the current.

 

And that's before we look at the MGU-H on F1 cars.

 

Not so much snake oil but possible future tech?

 

Lee

Err, the power consumption is Amps * Volts, regardless of whether the Volts are 6 or 6 thousand! In other words, the power needed to supply a given volume of air at a given pressure is a constant (near enough) regardless of the motor voltage and amperage.

 

F1 I don't fully understand, but what I think I do get is that they extract some electrical power from the exhaust gas (as well as the direct KE used to run the turbo-compressor), and some electrical power from regenerative braking. Extracting exhaust energy to propel a vehicle is well-known technology (see https://en.wikipedia.org/wiki/Scania_K-series and cross-references), as is using regenerative braking.