Why are new 4-pot petrols so coarse?

Sebastienclement · 6th May 2016, 08:00

Sorry for a non-rover question, chaps.

I've had the misfortune to be driving a few modern hire cars lately. All have been petrol and have included:

Insignia
Meriva
MINI
Focus
Fiesta

The one thing in common that all the cars had was a really rough / coarse petrol engine. They all felt like the didn't really want to rev past 3000 rpm, were noisy for a few seconds past startup & generally didn't feel smooth or well balanced engines.

I'm assuming it's some mandatory emissions rubbish that means they don't run as smoothly as older engines used to?

All the K series engines I've owned, despite their shortcomings, have been silent at idle inside the car, and almost silent standing next to the car at idle. They all revved freely, and generally were decent to drive.

The same goes with the 90s fords and Vauxhalls I've owned. All free revving, quiet, refined engines.

What gives?!

Darcydog · 6th May 2016, 08:12

I know what you mean - I suspect it is the emissions gubbins strangling the poor things.

That said one reason why we went for the car we did was because it was so smooth - and interestingly we went for a 1.4 rather than the 1.6 version because the 1.6 was exactly as you say - it seemed harsh compared to the smaller engine.

The Car is a Hyundai i30 Tourer - The smaller 1.4 engine is certainly no power house and I really miss the mid-range whoosh I get from the cdti - but round town it is an absolute delight. But having driven both the 1.6 petrol version and the 1.4 petrol we both felt the 1.4 was by far the "sweeter" engine.

The 1.6 did have more oomph - but you "knew it" if you know what I mean.

allegroman · 6th May 2016, 12:17

I've noticed (having driven quite a few hire cars) that unless you drive one fresh off the transporter most of them are quite rough. Brakes, gearchanges, engines, all seem wrecked by about 7,000 miles.

Modern engines do seem quite vile in general though, the only ones I've liked are whatever it is in the Fiat 500X and Jeep Renegade, and the Golf GTD (a brilliant engine)

JimSharp39 · 6th May 2016, 12:24

You know the oldest car joke in the world of course...

Whats the fastest car in the world?

....a rental...

Lord of Hog · 6th May 2016, 12:31

My 05 plate Outlander is hardly a new car but it does have the wonderful 4G69 4-cylinder 2.4 litre which rumbles away in a very pleasing fashion. The 1.4 in my K12 Micra chatters like a rev-happy sewing machine. Of course nothing can compare to the kamikaze howl of my old FTO Chavmobile as 9k came up on the rev counter ... but then that was a V6.

MSS · 6th May 2016, 15:51

Quote:

Originally Posted by Sebastienclement

....I'm assuming it's some mandatory emissions rubbish that means they don't run as smoothly as older engines used to?......

The lean running and emissions technologies, whch are intended to limit such things as brain tumours in future generation, do impact the smoothness of modern engines.

first-things-first · 6th May 2016, 15:54

Quote:

Originally Posted by mss

The lean running and emissions technologies, whch are intended to limit such things as brain tumours in future generation, do impact the smoothness of modern engines.

Quite true. I think a lot of modern petrol engines have EGR's to help lower emissions. Those hamper responsiveness on diesels.

Ross R75 · 6th May 2016, 22:57

Modern bikes are exactly the same. It's almost impossible to find one that fuels smoothly and doesn't have minor surging at low throttle openings. Emissions regulations mean that they run impossibly lean at low throttle.

Petetourer · 7th May 2016, 10:13

You will probably find that the focus and fiesta had the 3 cylinder Ecoboost engine fitted. They do sound a bit uneven due to this and actually sound a bit fruity when revved because of it.

Pretty good engine though and available with up to 140 Bhp

Quote:

Originally Posted by Sebastienclement

Sorry for a non-rover question, chaps.

I've had the misfortune to be driving a few modern hire cars lately. All have been petrol and have included:

Insignia
Meriva
MINI
Focus
Fiesta

The one thing in common that all the cars had was a really rough / coarse petrol engine. They all felt like the didn't really want to rev past 3000 rpm, were noisy for a few seconds past startup & generally didn't feel smooth or well balanced engines.

I'm assuming it's some mandatory emissions rubbish that means they don't run as smoothly as older engines used to?

All the K series engines I've owned, despite their shortcomings, have been silent at idle inside the car, and almost silent standing next to the car at idle. They all revved freely, and generally were decent to drive.

The same goes with the 90s fords and Vauxhalls I've owned. All free revving, quiet, refined engines.

What gives?!

RobSun · 7th May 2016, 11:48

I had two petrol hyundias both from new. The first a 2010 was really rough on tick over and ran as if on three cylinders after a motorway run. No power over 4000 rpm. Two dealers both said run it for about 3500 miles and it will smooth out so it must have been a common complaint. It did smooth out a bit but only a bit. The fuel consumtion was also nothing like that claimed and salesmen said it was poor and below what it should get but the service manager said the consumption was bang on what to expect from one. In comparison my zt-t diesel was/ is smoother and gives better consumtion.

The second new in 2013 was a vast improvement, smooth as silk engine would pull to the red line, couldn't tell it was running on tick over and much better fuel consumption on a par with the zt-t. It had the same engine as the first but with a little more bhp so they had been working on it. Unfortunately it was very unreliable, broke down with engine management fault after 3 days and kept on having management and mechanical failures for the first year. It was so bad It only had 1700 miles at its first service. Then the engine would just cut out at low speeds or stopped and they didn't know why or could fix. When it started cutting out at higher speeds and they still couldn't find out why and Hyundai actually said it had no faults it went. Only done 4700 miles.

After being dissapointed with other smaller modern cars and not finding anything I liked the ZT-T is the only one for me now ( at least whilst it continues to give me reliable service) and my Dolomite for those special days. Good old British character.

6th May 2016, 08:00	#1
Sebastienclement Posted a thing or two Rover 75 Connoisseur SE Join Date: Nov 2012 Location: London Posts: 1,237 Thanks: 136 Thanked 160 Times in 85 Posts	Why are new 4-pot petrols so coarse? Sorry for a non-rover question, chaps. I've had the misfortune to be driving a few modern hire cars lately. All have been petrol and have included: Insignia Meriva MINI Focus Fiesta The one thing in common that all the cars had was a really rough / coarse petrol engine. They all felt like the didn't really want to rev past 3000 rpm, were noisy for a few seconds past startup & generally didn't feel smooth or well balanced engines. I'm assuming it's some mandatory emissions rubbish that means they don't run as smoothly as older engines used to? All the K series engines I've owned, despite their shortcomings, have been silent at idle inside the car, and almost silent standing next to the car at idle. They all revved freely, and generally were decent to drive. The same goes with the 90s fords and Vauxhalls I've owned. All free revving, quiet, refined engines. What gives?!

6th May 2016, 12:17	#3
allegroman Gets stuck in Rover 75 Tourer CDT Club SE: BRG, Deep Sea Green and plenty of options Join Date: Jul 2007 Location: Plymouth Posts: 984 Thanks: 126 Thanked 62 Times in 31 Posts	I've noticed (having driven quite a few hire cars) that unless you drive one fresh off the transporter most of them are quite rough. Brakes, gearchanges, engines, all seem wrecked by about 7,000 miles. Modern engines do seem quite vile in general though, the only ones I've liked are whatever it is in the Fiat 500X and Jeep Renegade, and the Golf GTD (a brilliant engine) __________________ I used to be with it. Then they changed what it was.

6th May 2016, 12:31	#5
Lord of Hog Gets stuck in Rover 75 2.5 V6 in Wedgwood Blue Join Date: Dec 2015 Location: Felbridge, East Grinstead Posts: 982 Thanks: 250 Thanked 294 Times in 206 Posts	My 05 plate Outlander is hardly a new car but it does have the wonderful 4G69 4-cylinder 2.4 litre which rumbles away in a very pleasing fashion. The 1.4 in my K12 Micra chatters like a rev-happy sewing machine. Of course nothing can compare to the kamikaze howl of my old FTO Chavmobile as 9k came up on the rev counter ... but then that was a V6. __________________ Conformity is not morality. Consensus is not truth.

6th May 2016, 22:57	#8
Ross R75 Posted a thing or two Rover 75 Saloon Join Date: Apr 2007 Location: Edinburgh Posts: 1,535 Thanks: 137 Thanked 229 Times in 156 Posts	Modern bikes are exactly the same. It's almost impossible to find one that fuels smoothly and doesn't have minor surging at low throttle openings. Emissions regulations mean that they run impossibly lean at low throttle. __________________ Copperleaf R75 CDT 160

6th May 2016, 08:12	#2
Darcydog This is my second home Join Date: Jul 2014 Posts: 5,428 Thanks: 3,123 Thanked 3,170 Times in 2,096 Posts	I know what you mean - I suspect it is the emissions gubbins strangling the poor things. That said one reason why we went for the car we did was because it was so smooth - and interestingly we went for a 1.4 rather than the 1.6 version because the 1.6 was exactly as you say - it seemed harsh compared to the smaller engine. The Car is a Hyundai i30 Tourer - The smaller 1.4 engine is certainly no power house and I really miss the mid-range whoosh I get from the cdti - but round town it is an absolute delight. But having driven both the 1.6 petrol version and the 1.4 petrol we both felt the 1.4 was by far the "sweeter" engine. The 1.6 did have more oomph - but you "knew it" if you know what I mean.

6th May 2016, 12:24	#4
JimSharp39 Loves to post Rover 75 saloon Join Date: Jun 2015 Location: Kirkcaldy Posts: 265 Thanks: 65 Thanked 48 Times in 41 Posts	You know the oldest car joke in the world of course... Whats the fastest car in the world? ....a rental...

7th May 2016, 11:48	#10
RobSun Gets stuck in MGZTT Join Date: Feb 2015 Location: Bradford Posts: 529 Thanks: 148 Thanked 256 Times in 138 Posts	I had two petrol hyundias both from new. The first a 2010 was really rough on tick over and ran as if on three cylinders after a motorway run. No power over 4000 rpm. Two dealers both said run it for about 3500 miles and it will smooth out so it must have been a common complaint. It did smooth out a bit but only a bit. The fuel consumtion was also nothing like that claimed and salesmen said it was poor and below what it should get but the service manager said the consumption was bang on what to expect from one. In comparison my zt-t diesel was/ is smoother and gives better consumtion. The second new in 2013 was a vast improvement, smooth as silk engine would pull to the red line, couldn't tell it was running on tick over and much better fuel consumption on a par with the zt-t. It had the same engine as the first but with a little more bhp so they had been working on it. Unfortunately it was very unreliable, broke down with engine management fault after 3 days and kept on having management and mechanical failures for the first year. It was so bad It only had 1700 miles at its first service. Then the engine would just cut out at low speeds or stopped and they didn't know why or could fix. When it started cutting out at higher speeds and they still couldn't find out why and Hyundai actually said it had no faults it went. Only done 4700 miles. After being dissapointed with other smaller modern cars and not finding anything I liked the ZT-T is the only one for me now ( at least whilst it continues to give me reliable service) and my Dolomite for those special days. Good old British character.