Hi All,

I have recently traded in my 2012 M37 for a 2018 Q70. Am I crazy or is the road noise significantly louder in the newer version?

I had a '17 Q70 3.7 as a loaner a while back; it was more quiet than my '12 M56 but I'm comparing the V6 to the V8 plus I have a custom exhaust. They are not as quiet as they should be IMHO.

In a word ... yes. The 2006-2010 were the quiet years - only compared to the later models - none are quiet enough to be known as 'quiet'. Beginning with the M37's / 56's Infiniti shrank the body size and although newer generations 'look' similar in the cabin, the quality has decreased and after 2010, some previously standard features have either been dropped, or have become expensive options. Tech was improved and augmented twice, but that has naught to do with quiet. One can assume that Infiniti also has cut corners on insulation and noise reduction with each new generation as well.
As for road noise (if that is part of what you include as 'noise' in your question) ... I leave that to tires. Infiniti, and most other upscale car makers would not use crap tires like Cooper or any number of the Chinese tire brands, but they DO use whichever brand negotiates the lowest bulk rate whilst meeting minimum standards. That said, if your tires are ho-hum or average quality like General, Goodyear, Bridgestone, etc ... you aren't getting the quietest ride or best performance and handling. Upgrading to Michelin, Pirelli, Continental, etc will reduce road noise and increase performance / handling. Also the 'category' of tire is important.

Choose a tire best suited for your situation - temp fluctuation, snowfall, summer rated or all-season, etc. Generally speaking, summer rated tires are more comfy and less noisy, but also provide lower performance / less precise handling than all season or winter rated tires. Consider the following tire categories:
Ultra High Performance: these are higher priced, will perform best in most weather conditions, but less quiet than the other categories due to beefier construction
High performance: similar in price with slightly less noise but also less performance than 'ultra'
Grand Touring: A blend of performance and soft comfy ride - generally preferred for road trips in the family sedan or minivan
Touring: a blend of quiet and performance that bends toward comfort and away from performance

Also consider adding noise / vibration / insulation products like Dynamat, Dynaliner, Noico, Kilmat, etc to areas like the trunk, floor, and inner door surfaces.
I applied Dynamat in my trunk and Dynaliner under my carpeting and the difference was night and day. I can honestly say that even with my doors untreated, my car is very close to quiet as a Mercedes S-600 sedan. If you've ever rode in one, that is a very high benchmark.

To the OP, here s a thread with what another member did to help his road noise - road-noise-sound-deadening-t622413.html
He also opined that the older vehicles were quieter.
To him, I had suggested he addresses his wheel+tire situation first, but I'm guessing yours has the base model wheel + tire combo already?

Larz wrote: ↑

Sat Sep 07, 2019 9:42 am

In a word ... yes. The 2006-2010 were the quiet years - only compared to the later models - none are quiet enough to be known as 'quiet'. Beginning with the M37's / 56's Infiniti shrank the body size and although newer generations 'look' similar in the cabin, the quality has decreased ...

Larz, I think OP was referring to the earlier part of the current generation, 2011-2019. However, I wanted to address the quoted text as I have seen it come up a few times. This is based on ownership and regular operation of both generations of the Infiniti M.

The exterior dimensions of the vehicles are very close, with the 2011 generation seeming a little larger visually.
The interior dimensions are also very close although on paper, the pre-2011 models seem more spacious. I am not sure what methods are used to calculate these dimensions, but I guarantee that the 2011+ models feel more spacious. The seat design allows for more usable space. At 6'2", I am comfortable sitting behind the driver's seat pushed all the way back in my pre-2011 vehicles, but there is even more room in the 2011+ cars.
The trunk does seem a little better configured as well.

Quality is a different story altogether, but I've always felt that the features got nicer/cooler while the tactile quality got cheaper over time.

This is the chart I found when I researched the last time interior volume was discussed. It clearly shows how the M has shrunk during later generations and also shows exactly how much roomier the Q70L is compared to the previous generation Ms .... that is, IF the chart (from Edmonds) is accurate. It shows a reduction of 5 cubic inches after the M35/45 generation. That's a very small difference, but for some reason, everytime I drive a newer model, it 'feels' much smaller. I reckon it's up to my perception and not much else.

................M35 / M45....M37 / M56.....Q70.......Q70L
F leg room.......45.3..........43.3 .........43.3 ......43.3
F hip room.......55.1......... 53.3 .........53.3.......53.3
F head room.....40.1..........39.1..........39.1.......39.1
R leg room.......37.3..........36.1..........36.1.......41.8
R hip room.......53.9..........52.5..........52.5.......52.5
R head room ....39.6..........38.1..........38.1.......38.1
INT Cubic Ft....107.3.........102.6........102.6......125.5