To be a completely scientific test, yes, you would need fresh oil vs fresh oil. I am not going to waste 5 quarts of oil and a filter for that.
The car has never been quieter in the 3 years I have owned it.
Your engine is not stock. Simply changing the air filter system will make a huge difference in the vehicle's sound.
Is your 2.5L tuned to 245 horsepower, as claimed? How? I am genuinely curious, that is a big power number and impressive for the 2.5 without a power adder.

Also, is it a CX-5? Not all Mazdas have the same sound insulation or body design.

 

I spend the October - March period in Arizona & the rfest of the year in Alberta (April in Alberta is quite cold) Would the switch benefit me? What's the downside? Would Mazda still warrant the vehicle?

 

Mazda says 5W-30 is good from -20F+. Average low of 31F in April, and warmer in the summer...
As far as the dealer, you can call and ask them if you are concerned about that. Or you can have a qualified independent shop change your oil, almost certainly for less money if you call a few shops, and better yet, you can supply a higher quality oil and filter.




By the way, Callisto and anyone else, give Dark Reader a try, your eyes will thank you.

https://chrome.google.com/webstore/d...bieeh?hl=en-US
https://addons.mozilla.org/en-US/fir...on/darkreader/



Would you like a quieter vehicle at idle and cruising speed? Then the answer is yes.

Side note, I am now curious why you live in both the U.S. and Canada.

 

I would assume he goes south in the winter to escape the brutally cold Canadian winters??

 

He has an extensive thread on the mods he has done to his 3 should you want to peruse it. I too seriously wonder how his motor makes 245 WHP (which is over 280hp at the crank) with no forced induction as my 2.5T only generates 250hp at the crank.

 

Um well not sure where to start...lol.
Couple of things you should look into'
Mazda does not use the current certification for published power output. So, one would really say that MAZDA specification for power output is "CLAIMED"
And to achieve the level of reducing emission output to qualify to sell and use Mazda vehicles in the USA must comply with The Clean Air Act requires that all engines and vehicles be covered by a certificateof conformity before they can enter into commerce. So, the auto manufacture is very concerned to make sure that in the oil viscosity guide and SAE rating that you use the oil that support their engine complying to the standards required for lowering emissions.

As for my engine, most of the different oil viscosity I have used were before changing hard parts on the engine. The intake will make more noise but really only when there is a higher airspeed going through the intake system not at idle and really not at highway cruising speeds.
As far as the power info in my signature it's not claimed. I don't fudge numbers! lol but we can continue that on why it's not on your thread about your "GOOD" choice of viscosity to use with your Mazda or let it go? But before you answer I have owned/operated 3 different Dyno in my own shops, engine, chassis and portable Dyno. I have been doing accurate and repeatedly Dyno testing and fun runs on a few thousand vehicles and engines over a few decades. The video was taken close to the engine parts to collect all the "NORMAL" sounds created by a 2.5 Skyactiv engine. ROLMAO. I will say that my engine has some of my personally engineered internal parts installed that either support or increase the power output. And yes, the ECU is Performance calibrated. I do that professionally on one specific platform and model to support my performance line of parts since 2004 but also both a couple other platforms for fun, Mazda being 1 of them. Currently I am using the VersaTune program hard and soft ware to do my personally calibration. The 2.5 is N/A is capable of making even more power than what I decided was overall the most reliable for my use engine & Transmission safe output. The Turbocharged version currently offered can be upgrades to make much more power, but the transmission will not be reliable and fail in their present unmodified stock form.

I think you may be misreading my responses in this thread or reading into them to much? HA! . I supported your thoughts of using the oil viscosity you choose. But let's not bring up debatable information like what Mazda cleverly worded owner's manual oil use guide is. As for asking a Mazda dealer they read the same basic information. Unless there is someone employed that has some educational background on the study of motor oil like a Chemical Engineer. HA! Otherwise, dealer information on what they use and say is recommend will vary considerably from dealer to dealer. The only time should be concern is if the wording for oil viscosity says from the auto manufacture "TO USE ONLY" Thankfully we in the USA have the Magnuson–Moss Warranty Act(P.L. 93-637) which the auto manufacture is very careful how they word anything having to do with difference between "recommend" and "Required".

The best thing for some thread like this is to post what you use and leave it at that. Otherwise, be prepared for all the armchair experts to start to pound the keyboards and flood the thread full of information they specifically will look for that supports their choice of oil use. Very few if any have tested


Lastly it does not matter the model in general the sound reducing material has to do more with the level of model chosen and not that one may be a 3 ,6 or CX5 . And the engine noise is really relatively that same with all the skyactiv GAS engine compartments no matter which model Mazda from I would guess 2014 and newer!

 

Wow! almost a nice response having to do with me. But normally you include the *http when referencing other threads on this forum
chick I hate to be the one to tell you but your engine does not make 250hp at the crank. Go get your Madza Dyno'd.
Read information about Engine Power Test Code Certification which require be followed by auto manufacture to publish actual engine power information. Mazda does not follow or use it when publishing engine output information.
And read my signature again exactly what I wrote.

Mazda3 Things I like to do - Mazda Forum - Mazda Enthusiast Forums


This also helps with understanding my background and how I may not be an average DIY (Do-It_Yoursef) .

What do you do or have done for a living - Mazda Forum - Mazda Enthusiast Forums

 

I'm a resident of Canada with a home in Alberta. I snowbird in Arizona during the October - March time frame. If you have ever spent a winter in Alberta you wouldn't wonder why.😁