Monday, 6 October 2008

Quest for the quietest car

A good quality car is the one that cruises about as quietly as possible and isolates its passengers from noise, vibrations and harshness of the ride. Shouting? Growling? When you put your foot down, yes, it may be desired by some. But for another 99% of the time you want it to whisper, not to cause a headache.

All measurements are in decibels. While the decibel as a way of measuring intensity of noise is a complex term, it can be very easily demonstrated. There is an excellent webpage with flash animations presenting you noises decreasing by 3 or 1 or 0,3 decibels. Try it. This will allow you to see the differences between compared cars. It’s essential to realize that decibel is a logarithmic measure which means that relatively large changes in noise level result in little changes in decibels measured.

Then look at this chart to see what's what in terms of noises around us.

noises


The list of cars has been ordered by the noise measured inside the car at 70 mpg (~112,5 km/h). If results were equal, a noise at full throttle was considered - the lower, the better. Source is Edmunds InsideLine full or comparison tests. To put V8 diesels in perspective, two additional cars: Audi A8 4.2 TDI and BMW 745d were measured by Auto Motor und Sport at 100 and 130 km/h. Measurements were then interpolated and floored (rounded down to the nearest integer).

The upper part of the list almost certainly contains the quietest cars on the market today. The lower may not be as representative. Some cars absent here may land somewhere between the ones measured and placed there.

A clear conclusion is that while the top is occupied by very expensive vehicles, it is by no means a necessity to spend a lot of money to get a really silent car.

In case of some cars like BMW 335i and Toyota Prius, more than one measurement was available. Lower results were picked in such cases as one can assume that readings in noise level measurement procedure can much easier be overstated (due to presence of additional noise sources like something outside the moving vehicle during the test) than understated. It's nearly impossible to unintentionally make test noise readings lower in a vehicle cruising at a given speed.

Format is: the rank, the car and noise level in decibels
at 70 mph (~112,5 km/h)
at full throttle
when idling




1. Lexus LS 600h L
58,9
66,6
38,3

Anything this Lexus does, it does it quieter than Rolls Royce Phantom. Not bad!

The only car that can possibly beat the largest hybrid is the Maybach. Edmunds InsideLine did a full test of it and... they didn’t measure noise levels!

2. Rolls Royce Phantom
59,0
67,0
40,0

The Queen Elizabeth is where she's supposed to be - at the very top of the list.



3. 2008 BMW 535i
61,2
70,7
43,1
That's a true surprise, to see this Bimmer here. But when one thinks about it for a second, it becomes somewhat logical. The 535i has a twin-turbo petrol straight six. High torque due to charging means little revs are needed to cruise what decreases the noise. And then come the turbines themselves, clogging the exhaust manifold and quieting the car even more. Excellent performance from an unsuspected contender.

4. Mercedes-Benz S550
62,0
66,0
48,0

It was certain to find this car close to the top.

5. Lexus LS 460
62,5
68,3
37,2

LS460 follows its hybrid version closely.



6. 2007 BMW 335i
62,5
76,3
46,9
Like father, like son, the 335i twin-turbo handsome looking brute benefits from the same quietly beating yet potent heart.

7. Mercedes-Benz GL450
62,6
72,5
42,6
Big powerful SUV means there's lots of space and carrying capacity for decent sound insulation. Big V8 in low revs doesn't shout either.

8. 2005 Land Rover LR3
63,0
69,0
Low

Softly-sprung LR3 is an oasis of comfort also in terms of noise level.


9. 2006 BMW 650i
63,1
71,5
45,0

A transcontinental grandtourer can growl a bit when floored but has to whisper when not.

10. 2009 Hyundai Genesis V8
63,3
72,3
43,8

Can you recall all those people mocking Korean cars and disrespecting these as cheap and nasty econo-boxes?



11.2009 Hyundai Genesis V6
63,5
70,8
39,6



12. 2007 BMW X5 4,8i
63,6
77,6
46,0





13. BMW 750i
64,0
69,0
45,0



14. 2007 Mercedes-Benz CL600
64,0
70,5
43,0

Jeremy Clarkson calls this car "the new King of the Road"


15. 2006 Land Rover Range Rover Supercharged
64,0
72,0
Low

Louder than the LR3.



16. 2009 Audi A4 3,2 V6
64,0
72,8
43,5

Handsome looks, front axle shifted forward, rear-biased quattro, small petrol engines all fitted with turbochargers - very good. And now it turns out the B8 A4 is also very quiet.


17. BMW 745d
64,0
unknown
unknown



18. 2007 Jaguar XK
64,2
77,2
45,5



19. 2007 BMW X3
64,2
71,8
40,5

Very quiet for a not that expensive compact SUV.




20. 2007 Lincoln MKX
64,3
72,6
48,4

Same can be said about this Lincoln.

21. 2007 Mercedes-Benz E550
64,4
70,8
45,9



22. 2007 Lincoln MKZ
64,5
73,2
46,9



23. 2009 Lincoln MKS AWD
64,6
74,5
44,0






24. Volkswagen Touareg 2 V8
64,7
71,6
42,6



25. Lexus GS 350
64,7
72,2
39,2



26. 2006 BMW 550i
64,8
69,4
42,7




27. Mercedes-Benz E320 CDI Bluetec
65,0
68,8
45,5





28. 2006 Mercedes-Benz ML350
65,0
69,0
41,0





29. 2008 Toyota Highlander Hybrid
65,0
69,6
42,4

Decent result - the Highlander Hybrid makes sense not only in terms of fuel economy but also the quiet ride.


30. Bentley Continental Flying Spur
65,0
73,0
46,0
You'd expect the big Bentley to fare better, wouldn't you.

31. 2008 Mercedes-Benz C350 Sport
65,2
75,8
43,3



32. 2008 Land Rover LR2
65,3
74,5
42,3






33. 2007 Bentley Continental GT
65,5
72,4
50,4





34. 2007 Volvo S80 V8 AWD
65,5
79,6
44,5



35. 2006 Audi A6 4,2 Quattro S-Line
65,6
70,4
47,5




36. 2007 Mercedes-Benz GL320 CDI
65,8
71,3
46,1






37. 2007 Lincoln Navigator L 4WD
65,8
75,0
42,3




38. Audi A8 4.2 TDI
66,0
unknown
unknown

Not as refined as its petrol rivals.


39. 2009 Acura TSX
66,1
74,9
41,8



40. 2008 Nissan Altima 3.5 SE
66,2
73,6
41,7





41. 2007 Mercedes-Benz SL65 AMG
66,3
74,0
47,7

SL can be excused by its retractable hardtop, one of the best inventions in car body design.

42. 2008 Toyota Camry Hybrid
66,7
73,1
46,8 (engine on) 42,4 (engine off)
Good result for a relatively inexpensive car the Camry Hybrid is, to see it among much more pricey vehicles.


43. 2006 Porsche Cayenne Turbo S
66,8
73,8
42,4





44. 2007 BMW M6
66,8
77,7
58,0





45. 2007 Infiniti G35 Sport
66,9
77,6
41,4


46. 2006 Land Rover Range Rover Sport Supercharged
67,0
69,0
48,0





47. Lexus GS 450h
67,0
73,6
37,5

Disappointing. Its petrol counterpart is much higher in the rank.



48. Audi A8 W12 L
67,0
75,6
44,5

Is it really the ultimate luxury sedan from Audi, so low in the rank?


49. 2007 Cadillac Escalade
67,1
78,4
44,8

Quieter than rap music its stereo plays all the time.

50. 2009 Mazda 6
67,1
80,1
44,1

Mazda 6 fares well in quietness department also.



51. 2008 Honda Accord EX-L
67,3
73,1
44,7


52. 2005 Jaguar Super V8
67,5
73,6
48,0



53. 2007 Lexus ES 350
67,5
74,6
41,0





54. 2008 Cadillac CTS
67,5
82,9
43,3




55. 2008 Toyota Prius II
67,7
70,6
47,2 (engine on) 40,7 (engine off)

The lightweight hybrid has no chance of having thick sound proofing, still performs well, most likely thanks to CVT gearbox which can adjust engine revs as precisely as needed and low drag decreasing wind noise.


56. 2009 Jaguar XF Supercharged
67,8
72,5
46,8

In the past, big cats used to tiptoe when moving about.

57. 2006 Volkswagen Passat 2.0T
68,3
71,2
45,8

This is a turbocharged car so same principles as in case of twin-turbo bimmers should work also. They don't. Little sound insulation?

58. Audi S5
68,8
77,2
42,5

The handsome S5 was born to growl so its poor performance can be somewhat excused.

59. 2007 Volkswagen Passat Wagon 3.6 4Motion
68,9
73,3
44,0




60. 2008 Lexus IS 350
68,9
77,9
38,6

Loud.

61. 2005 Acura RL
69,0
71,0
unknown

Lots of good things can be heard about Acuras so I was expecting these to fare much better.






62. 2007 Acura RDX turbo
69,4
75,2
41,4


63. Audi Q7 4,2
69,8
74,1
45,0

After achieving scary fuel economy of 11,2 MPG in Edmunds InsideLine full test, the big Audi finds itself quite low in this rank too. The Merc GL450 achieves 15 MPG and is at the opposite end of the list.


64. 2009 Volkswagen Jetta TDI
70,0
72,8
47,7

Very good for a small diesel sedan. The common rail injection smoothers the rattle. Typical for a diesel, high low-end torque allows the car to cruise at low revs and helps too.


65. 2005 Cadillac STS
70,0
73,0
unknown


66. Volkswagen Phaeton W12
70,0
73,0
unknown

As the fifteenth child of dr Ferdinand Piƫch (yes, he really has 13 children, the 14th is the Bugatti Veyron) this car cries rather loud as for an ultimate VW sedan.

67. 2004 Infiniti QX56
70,0
75,0
unknown




68. 2003 Bentley Arnage R
73,0
75,0
51,0

No comments. This car weight nearly 2600 kg (~5700 pounds), has an engine from a locomotive which barely has to rev to power the car along and yet it finishes last here.



Late entries - after tidying up the post I realized Volvo XC90 wasn’t enrolled. So quick check places it as follows: the 2003 2.5 turbo is out of business with its 75 dB, the 2005 with Yamaha V8 (68 dB) is placed between Jaguar XF Supercharged and VW Passat 2.0 turbo and the 2007 V8 Sport performs very well and with it 64 dB and 84 dB (cruising and full throttle) lands somewhere after the BMW 745d.


References

2009 Acura TSX
2007 Acura RDX turbo
2005 Acura RL

Audi Q7 4.2
2009 Audi A4 3.2
Audi A8 W12 L
2006 Audi A6 4.2 Quattro S-Line
Audi S5

2007 Bentley Continental GT, 2007 Mercedes-Benz CL600
2003 Bentley Arnage R
Bentley Continental Flying Spur

2007 BMW X5 4.8i
2007 BMW X3, 2008 Land Rover LR2
BMW 335i Coupe
BMW 750i
2008 BMW 535i
2006 BMW 550i
2007 Jaguar XK 2006 BMW 650i
2007 BMW M6 2007 Mercedes-Benz SL65 AMG

2005 Cadillac STS
2007 Cadillac Escalade

2009 Hyundai Genesis V8
2009 Hyundai Genesis V6

2004 Infiniti QX56
2007 Infiniti G35 Sport, 2007 BMW 335i, 2008 Cadillac CTS, 2008 Lexus IS 350, 2008 Mercedes-Benz C350 Sport

2005 Jaguar Super V8
2009 Jaguar XF Supercharged

2006 Land Rover Range Rover Sport Supercharged
2006 Land Rover Range Rover Supercharged
2005 Land Rover LR3

Lexus LS 600h L
Lexus LS 460
Lexus GS 450h
Lexus GS 350
2007 Lexus ES 350

2007 Lincoln Navigator L 4WD
2007 Lincoln MKX
2007 Lincoln MKZ
2009 Lincoln MKS AWD

2006 Porsche Cayenne Turbo S

Rolls Royce Phantom

2008 Mercedes-Benz GL320 CDI
2006 Mercedes-Benz ML350
Mercedes-Benz S550
Mercedes-Benz E320 CDI Bluetec
Mercedes-Benz GL450

2009 Mazda 6, 2009 Mazda 6, 2008 Nissan Altima 3.5 SE

2008 Toyota Highlander Hybrid
2008 Toyota Camry Hybrid, 2008 Toyota Prius II

2009 Volkswagen Jetta TDI
2006 Volkswagen Passat 2.0T
2007 Volkswagen Passat Wagon 3.6 4Motion
Volkswagen Touareg 2 V8
Volkswagen Phaeton W12

2007 Volvo S80 V8 AWD
2007 Volvo XC90 V8 Sport
2005 Volvo XC90 V8
2003 Volvo XC90 2.5T

16 response(s):

Anonymous said...

i'm amazed to see that the series that's synonymous with silence hasn't been mentioned here - the Lexus LS430. Not part of the lineup?

google said...

This is an *AWESOME* compilation - nice work! I've been looking for a list like this for some time now.

Best of all, the entries are all very recent.

Scott said...

The 2010 Subaru Outback gets a 61.1 db at 70mph?

Anyone believe this?

http://www.edmunds.com/subaru/outback/2010/testdrive.html

Scott said...

correction 63.1.

Still blows away the #1 Lexus if true.

Terryaki said...

2011 Kia Sorento
59.0 at 70 mph
66.9 at full throttle
34.1 when idling
Manufacturer and car magazines are claiming these numbers.
Wow.

Wilton mercedes GL450 said...

Mileage of all the above models are awesome. But in comparison to others, I want to know more about the above Mercedes model.

Buy Toyota Avensis said...

I hope you can continue this type of hard work to this site in future also..Because this blog is really very informative and it helps me lot.

connan Almonds said...

Lexus es350 is not on the list and yet lexus is is? Hmmmm

Anonymous said...

Thank you for this. GREAT information. Having difficulty finding it elsewhere.

Denkkar said...

For a very lengthy table of sortable noise comparisons for recent model years: http://www.auto-decibel-db.com/

John Curtis said...

I think that the stuff and research you have presented to find out the quickest car is really valuable. I also agree with the result which you have concluded from your hard work.
auto transport quotes

Stemphonyx said...

You need to be more specific. You don't mention anything about how the measurements were done and what type of dB you are using. is it dBA? is it dBC? it makes a huge difference. Also, are these measurements taken is exactly the same piece of road? it has to be done in a laboratory with exactly the same condition for each car. Be more specific.

J.T. said...

For far more data check out: http://www.auto-decibel-db.com/

Anonymous said...

More like bullshit numbers. Having been in many of the cars, these numbers are all sorts of screwed up. They're not done on the same road, they're not using calibrated equipment, and the cars that they say are quieter than others is comical. Sorento being that quiet?! Hah!

Nissan Mobil Terbaik Pilihan Keluarga said...

Wow i think i should bookmark this page

tyreon wheels said...

I read your awesome blog,thanks for sharing this information.If anyone wants to Buy Honda Accord Tyres Online in lowest price in delhi.