Gravity GT First Drive and Orders information

[hmp10]

I dno, I don't drive minivans

I do, and they have their own glories. But it's the Vredestein Quatrac Pro+ over the Hankooks for me. I'm more worried about wet handling than range in that car.

 

[JeffSter]

Sorry if that came off as trash talking. Just trying to bring some humor to this discussion.

Its ok… But I will never buy another GM or Honda car. GM legally, daily harassed me by phone me once over a safety defect buyback, Honda is the king of planned obsolescence… 2 transmissions in 120K miles… 60… and 60 again like clockwork. No thanks. None of this is usually that serious.

Seems that staggered sets are done to help keep traction in rear of car and not necessarily for only aesthetic reasons. If they are truly functional and not simply macho… then I’m good with it. I squared my old Model X and never noticed any functional diff.

I also don’t buy the truly crazy large wheels with a friggin rubber band around them that pop and crack the rims when they see a pothole. Hence I await 20/21 setup… love the 40 extra miles too.

 

[JeffSter]

I don't mean to sound snarky here, but I just don't quite get the concern about rotating tires to extract more tread life on a 6,000-pound car with more than 900 ft lbs of torque. It's simply not a vehicle that someone who is set on getting 40-60,000 miles out of a set of tires should be considering.

The ability to road trip the cars are highly influenced by the availability of replacement tires while out on the road. Longevity is not the only reason… was road tripping from CA to Houston TX and had a stupid puncture… no tire shops in TX wanted to touch the “special” tires on my Model X because of the acoustic internal foam. ContiSilents. I squared it and bought Michelins at my local costco from then on. Never even noticed the “noise” that the foam was allegedly helping with.

 

[TahoeMichael]

The ability to road trip the cars are highly influenced by the availability of replacement tires while out on the road. Longevity is not the only reason… was road tripping from CA to Houston TX and had a stupid puncture… no tire shops in TX wanted to touch the “special” tires on my Model X because of the acoustic internal foam. ContiSilents. I squared it and bought Michelins at my local costco from then on. Never even noticed the “noise” that the foam was allegedly helping with.

So, I guess the takeaway is: It's hip to be square?

Sorry, I'll show myself out.

 

[hmp10]

The ability to road trip the cars are highly influenced by the availability of replacement tires while out on the road. Longevity is not the only reason… was road tripping from CA to Houston TX and had a stupid puncture… no tire shops in TX wanted to touch the “special” tires on my Model X because of the acoustic internal foam. ContiSilents. I squared it and bought Michelins at my local costco from then on. Never even noticed the “noise” that the foam was allegedly helping with.

The few objective measures of tire noise reduction from foam blocks that I've ever seen show a difference of between 1 and 2 db. The smallest volume increment that most people can detect is around 3 db, which does make the whole "foam thing" seem kind of pointless.

Of course, since some tire noise is probably transmitted mechanically through the car's structure rather than just through the air, it may be that passengers are somehow more sensitive to tire noise level differences. But I've never seen anything saying as much.

 

[Pragmatic]

I heard (Camissa) that the foam was originally needed for the Model S to pass Federal drive by noise regulations.

 

[johnse]

difference of between 1 and 2 db. The smallest volume increment that most people can detect is around 3 db,

Sound levels are measured on a logarithmic scale. Every 3 db is a doubling of the sound level.

Just Noticable Difference decreases with volume. This article has some good data for pure tones.

7.1.4: Just Noticeable Difference

phys.libretexts.org

JND is significantly less than 1db above 40 db. For reference, 44 db is the lowest level of urban ambient environment. https://www.chem.purdue.edu/chemsafety/Training/PPETrain/dblevels.htm

I know when mixing music, a 3db change is quite significant in changing the balance between instruments or bringing vocals out of a mix.

 

[hmp10]

Sound levels are measured on a logarithmic scale. Every 3 db is a doubling of the sound level.

You have to double the energy to produce a 3-db increase in sound level. That does not mean, however, that the human ear perceives a 3-db increase as a doubling of volume. In fact, it takes about a 10-db increase in sound level to be perceived as a doubling of the sound level:

"The perceived loudness of sound will double for about every 10 dB increase in sound level (e.g., a 60 dB SPL sound may be subjectively twice as loud as a 50 dB SPL sound)."

Basics of Sound, the Ear, and Hearing - Hearing Loss - NCBI Bookshelf

 

[Xminus6]

The ability to road trip the cars are highly influenced by the availability of replacement tires while out on the road. Longevity is not the only reason… was road tripping from CA to Houston TX and had a stupid puncture… no tire shops in TX wanted to touch the “special” tires on my Model X because of the acoustic internal foam. ContiSilents. I squared it and bought Michelins at my local costco from then on. Never even noticed the “noise” that the foam was allegedly helping with.

I feel like it does make a difference but I’m not sure it’s worth the difficulty of dealing with the tires with foam. I remember driving my car to Costco to get the tires changed so I noticed the difference back-to-back. The newer tired without the foam didn’t seem louder from a regular road noise perspective but they have a sort of percussive, ballooning noise that was damped by the foam tires. It sounded faintly like the noise of hitting a yoga ball.

I obviously got used to it but I could most definitely hear the difference.