Not the world's most knowledgeable about the mechanics, engineering or physics of the ICE, but have had a lot of experience driving loads of different cars and have some other random/useless thoughts on the topic from a lifetime of driving low powered vehicles!
Recently we had a long term hire car, a 1L Dacia Jogger. On the whole in general usage it was smooth, quiet, nippy enough and frugal. Where it lacked was pulling-power up steep hills requiring much stick stirring, and when fully loaded - 4 adults + 2 dogs for example. As we live in deepest Devon, hills are an issue, but you get used to it. When 4 up and there are hills that's more of an issue. Would I consider one? Depends - answer later....
We recently had a 2L Diesel VW Camper which we bought in a moment of madness/love to pull a 1.5 tonne caravan. Test driving the VW along flat roads it seemed pretty zippy considering all the camping gubbins and pop-top roof etc. It was only later on hills we realised that judicious use of gears and revs was required and the fuel consumption fell of a cliff. It was then we realised that whilst 2L it was only 102HP! Pulling the caravan up a long motorway drag was a slow process where we'd regularly be overtaken by trucks. So we were about to get it remapped to 130HP when on a long slow drag uphill drag at night when fully loaded som inattentive idiot hadn't noticed we were doing 50mph on the inside lane rather than 70 and drove into the back of me writing-off our beautiful van in the process :-(. We then looked at a 150HP auto replacement.
Over the years we have had a number of large motorhomes with 110, 130, 150 and 160hp engines and what I've noticed is that you don't seem to notice the power increases as much as you'd expect, part of that is because bigger engines 'tend' engines to be found in bigger heavier vans/Autos AND, even at equal weight, power is very quickly offset by Aerodynamics (which as cyclists we should appreciate).
Most will be familiar with my daily runabout - my 13 year old nearly 100k miles Citroen C1. It surprises people that I regularly travel long distances especially on Motorways with it's little 900cc 3 cylinder engine. I usually travel alone, and the C1 weighs bugger all. It's skinny wheeled and a blob- shaped so fairly aerodynamic. Apart from some very steep hills it powers along well with the beautifully turbine smooth 3 cylinder Toyota engine spinning away. On the motorway on fairly flattish roads it will zoom along at 80mph very happily and give almost 50 mpg. Acceleration off the lights is initially OK but then soon gets left behind, but roll-ons on the motorway over 60mph to 80 when the engines spinning surprises bigger cars!
On the Specifics of 1L Dacia Duster, my thoughts are that unless I was using it as a run-around I'd be a tad wary. We've had 2 Dusters, the first a 1.6 Petrol which couldn't pull the skin off a rice pudding and had terrible fuel economy to boot, and the 1.5 Diesel which works perfectly and gives excellent MPG 45 to 50+ in general use Whilst the Duster is fairly light by small SUV standards it has fat trendy tyres and the aerodynamics of a brick and at higher speeds an longer journeys that has an impact. With the Diesels torque however it is very good when loaded-up.
This is a long ramble to make a couple of points.
Whilst big lazy low-stressed engines are fine and long-lived, they are heavy and inefficient as
@wafter eloquently explains. Smaller cheaper, lighter, free-spinning low capacity engines are smooth, efficient and on the whole sufficiently powerful for most people and most usages. So it boils down to horses for courses!
Small modern 1L 3Cyl engines are brill for most peoples car-usage with a couple of caveats!
- If it's mostly one/two people driving i.e not regularly 4 people and 2 dogs or a boot-ful of kiddy crap etc
- If the base car itself is relatively light
- If most of your driving is over relatively flatter terrain
- If most of your driving is Urban/A-roads
- If the vehicle itself has a reasonable aerodynamic shape and skinnier tyres
- If you're not regularly driving around with a roof-box/bike racks
- If you're not a wannabe Carlos Fandango!
Going back to whether I would purchase a 1L Jogger? If we didn't need to pull a caravan, probably yes. Mostly it's 1 person + 2 dogs or 2 person and 2 dogs so not a lot of added weight. We're quite used to low powered vehicles so a bit of stick-stirring and patience is in our elderly DNA. It suited our other needs and would be cheap to buy, insure and run.
In the end we didn't go for the 150HP VW auto camper either, partly because of the recent interest rate hikes, partly because of the stupidly increasing Insurance costs for VW campers and the 150HP while great for pulling the Caravan gave worse day to day fuel economy than our 102HP version. As it was to be Wimpers run-around, that would be a notable extra cost.
In the end we bought a 4 year-old diesel 150HP Auto low mileage Ford Galaxy! Something that wasn't anywhere on our radar! It was just sat there in the dealers when we chanced-by it. After a test-drive we bought it! In this instance with Caravanning future it was simply the right horse for our course. Heavy enough to pull the van, powerful enough to pull the van with a smooth 7 speed auto-box. Not too bad aerodynamically for a big car and for general pootling around 40 to 45 MPG (if I drive it anyhow).
That's a long waffle to state that I think small performance engines are great, BUT depending in what vehicle (weight, shape) and how you intend to use that car (weight, terrain, journey type).
Small is beautiful....
