The 3 pot in my new Swift is very quite and smooth, it's certainly quiter than the 1.4t in my previous Vitara and I always thought that fairly refined.

My son has a Aygo, 3 years old I think? The engine in that is certainly more vocal although he does tend to drive it fairly hard.

yaris hybrid . smooth car. doubt you would know it was a 3 pot

I changed from a 1.4 4 cylinder i30 to a 1.0 3 cylinder i10 and find it smooth, quiet and flexible up to 3000 rpm, cruises fairly quietly at 65 on motorways too.

If you use full throttle for overtaking or steep hills, it isn't excessively loud but I've had 4, 6 and V8 cylinder cars in the past and at full power engine was always audible.

3 cylinder engines sound different, but most aren't particularly rough sounding unless revved hard.

It would be worth the OP getting a test drive in another identical model to see whether the noise is normal for that car or not.

The VAG 1.0 TSI is a bit rough and rattly when heard from outside the car on cold starts (particularly when compared to the 4 cylinder Toyota engine in my car), but once the engine is warmed you'd barely know it was running when standing next to the car.

There's always the possibility, even on a nearly new car that it's been run when the oil is too low and 200000 miles worth of engine wear has happened in a few hundred miles.

Thank you all for your interesting comments.

We will test drive a Fabia and another Bayon/i20. It will be interesting to compare how they sound.

I listened to a 21 reg Kona today. It sounded different but not especially rough. I assume that is the same engine that's in the Bayon.

I'm guessing pretty much all cars in that segment/price range have 3 cylinder engines now?

I am a bit of a reluctant buyer. We're only changing now to cushion us a bit from the motoring insanity which is coming down the road (excuse the pun ).

Surprisingly, the VW 1.2 TDI 3-cyiinder diesel doesn't have a particularly noticeable 3-cylinder noise except when pulling hard or its tractor-like tickover. It has more of the distinctive VW TDI mechanical noise plus the whining of the camshaft gears (cambelt drives one camshaft, which drives the other through gears!!)

Edited by Sofa Spud on 28/11/2024 at 22:00

A 4-cylinder engine has 4 power strokes per 2 revolutions of the crankshaft, each covering 180 degrees of crankshaft rotation. One power stroke immediately followed by another.

3-cylinder has 3 power strokes per 2 revolutions, each covering 180 degrees of crank rotation. That means there is 60 degrees of unpowered rotation between each of the 3 power strokes (not counting the momentum of the flywheel).

That argument would only hold water if each cylinder on the 4 cyl engine had the same capacity as each on the 3 cylinder.

But they don't, each cylinder on a 3 cyl 1.2 is packing 33% more volume than a 4 cyl 1.2. So a bigger bang and more force being exerted on the crank, overcoming any gap, or unpowered rotation.

I'd also point out that we had a (n/a) 3 cyl Daihatsu Sirion for three years and it didn't suffer from the characteristics you describe (because it had appropriate gearing). Yet the 4 cylinder 1.7 turbo diesel Vauxhall Meriva which came next did (it had over-long gearing). I've also heard anecdotally from someone who had a Toyota Auris 1.4 turbo diesel and someone who had a Vauxhall Astra 1.3 turbo diesel, both 4 cylinder engines and both (according to their owners) suffering from the same problem (almost certainly due to over-long gearing)

It may well be that if a 3-cylinder car has the same gearbox as a 4-cylinder version of the same car, it would feel too high-geared, as 1600 rpm in a 3-cylinder feels like 1200 rpm in a 4.

That isn't the case though. Whether or not a car feels too high geared is determined by how much power and torque it has in relation to its weight, aerodynamics and (obviously!) gearing, not how many cylinders the engine has.

Edited by badbusdriver on 29/11/2024 at 08:31

Despite liking the Bayon we had a look at the Stonic and think we prefer that. I assume that has the same engine.

It does, they are basically the same car under the skin.

Our Bayon is a Motability car and was chosen mainly because it was a particularly good deal compared to other similar cars, including the Stonic. Have to say I do prefer the looks of the Stonic, but (in addition to the better deal) the Bayon counters with a bigger boot and more rear seat space (though neither are the most capacious in their class)

Looking on Autotrader, cheapest brand new Stonic listed is £19,835, but the cheapest Bayon is £18,485

Oddly enough I'm contemplating a Mazda 2 as a replacement for our Popemobile. Either petrol or mild hybrid. Has to be automatic.

I thought you liked your Mazda 2? Sensible cars, 4 cyl Skyactiv-G, proper autobox. The DSG on the Popemobile is a bit rougher than it used to be. Not having another of those.

Do the modern three cylinder engines need a counterbalance shaft driven by a chain which may become a maintenance issue ?