ASH8

http://www.popularmechanics.com/cars...eight-strategy



Mazda was so serious about weight loss when they designed their new CX-5 Skyactiv that they not only employed the usual trim-down techniques (more high tensile steel, less unecessary bulk), they employed a "gram strategy" approach that literally leaves no bolt untouched.

For example, look at an old seat bolt (right) and a new one (left.) The move to a reverse Torx head allows the lighter version to be screwed or unscrewed using a standard 10mm socket wrench. More crucially, it saves 8 grams per unit. That may not sound like a lot of mass, but minute alterations like that helps the CX-5 ditch anywhere from 288 lbs to 575 lbs compared to the outgoing CX-7, which has essentially the same interior volume.

Pretty sweet, huh?

dynamho

Cool.
Why do they say it's a reverse Torx head to confound things?
It looks like a standard bolt that's been carved out.

paimon.soror

iTrader: (15)

because the shape is literally the inverse of a torx head....?

dynamho

I don't have issue with the description, paimon.

To me, they made it sound as if there really is something called a reverse Torx head (as in pre-existing), for which there's a specialty tool for. This bolt works with a standard socket.

dozer

iTrader: (3)

ahhhh even the little things count. nice yob mazda


PS buttsecks.

paimon.soror

iTrader: (15)

Oh lol, yea but i suppose if you are using it in an application where a significant amount of torque is required, you would end up rounding off the points if you were using a standard socket.

dynamho

True.

In the original post Ash8 made, one of the comments (the only comment I think) in the link piqued my interest, but I'm having trouble getting clarity on what this guy means. It sounds like some sort of stress failure, but I can't picture da Fail.

"Sterling Calhoun · Memphis, Tennessee
Maybe they should talk to Suzuki and take some lessons from the GSXR series sportbikes. From the way this trend is going, there will be a hole right through the middle of the bolt next year (just like the brake caliper bolts on my bike)."

tjbourgoyne

Is this done for the entire car or just specific bolts?

56 bolts at 8 grams (roughly) = 1 lb. It would take a lot of bolts to make it worth while.

godesshunter

There is. Its nothing new. Its actually very common in European cars. Has been for years. The use of a standard socket can easily round off the head making it very difficult to remove after. The proper tool for the job looks like this.


Try doing rear brakes on a Saab or Volvo without one of these that is impact rated and you will have a bad day.

dynamho

Oh OK. Thanks godesshunter. Never seen one before.

Looks like the more standard term for that is External Torx.

Good to know.

godesshunter

There is some fancy name for it. I forget what it is but most mechanics refer to it as "inverted torx"

dynamho

So does this mean, Mazda's doing what the Europeans have been doing all along? ;D

godesshunter

Possibly. But at least Mazda has reasoning behind it. I'm sure the euros did it just to be obnoxious.

dynamho

ASH8

I call them a 'star' socket, but probably wrong..