# Car terminology: Someone englighten me. **URL:** \ **Category:** SON240sx Automotive\ **Created:** [February 12, 2005, 8:06pm UTC](https://forums.speedlife.net/t/car-terminology-someone-englighten-me/83631 "2005-02-12T20:06:06Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [February 12, 2005, 8:06pm UTC](https://forums.speedlife.net/t/car-terminology-someone-englighten-me/83631/1 "2005-02-12T20:06:06Z")
IBn00b. Q: What does **POT** stand for, when referring to brakes piston count? For example: _This brake kit has 4-POT calipers_. Now I know 4 is referring to the # of pistions, but what exactly does POT stand for? Q: What does **JJ** stand for, when referring to wheel widths? For example: _These wheels are 17x9JJ_ I’m looking for exact words for these acronyms and not really what they represent. ---
**Author:** ![NiTeRiDeR](https://avatars.discourse-cdn.com/v4/letter/n/dfb087/32.png) [@NiTeRiDeR](https://forums.speedlife.net/u/NiTeRiDeR)\ **Post date:** [February 12, 2005, 8:20pm UTC](https://forums.speedlife.net/t/car-terminology-someone-englighten-me/83631/2 "2005-02-12T20:20:31Z")
look at a caliper, the pistons look like POTS, that’s always what I assumed it meant… not an acronym… just slang term. 4 PISTON CALIPERS = 4 POT… May be wrong though… ---
**Author:** ![dnash](https://avatars.discourse-cdn.com/v4/letter/d/f6c823/32.png) [@dnash](https://forums.speedlife.net/u/dnash)\ **Post date:** [February 12, 2005, 8:42pm UTC](https://forums.speedlife.net/t/car-terminology-someone-englighten-me/83631/3 "2005-02-12T20:42:03Z")
POT is just the British way of saying it I think. ---
**Author:** ![Sasha\_SG](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/sasha_sg/32/5477_2.png) [@Sasha\_SG](https://forums.speedlife.net/u/Sasha_SG)\ **Post date:** [February 12, 2005, 9:11pm UTC](https://forums.speedlife.net/t/car-terminology-someone-englighten-me/83631/4 "2005-02-12T21:11:12Z")
J / JJ etc is the lip design the wheel has on the inside, for seating a tire. Its not really vital information to know ---
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [February 12, 2005, 9:29pm UTC](https://forums.speedlife.net/t/car-terminology-someone-englighten-me/83631/5 "2005-02-12T21:29:19Z")
But what do those letters stand for? POT or JJ? Or as stated earlier, since they are slangs, the letters don’t really have any definitions to them? :dunno: ---
**Author:** ![rotorkami\_wa](https://avatars.discourse-cdn.com/v4/letter/r/e36b37/32.png) [@rotorkami\_wa](https://forums.speedlife.net/u/rotorkami_wa)\ **Post date:** [February 12, 2005, 10:20pm UTC](https://forums.speedlife.net/t/car-terminology-someone-englighten-me/83631/6 "2005-02-12T22:20:38Z")
POT is becuse most 'pistons are hoolw on the backside hence it looks like a mini cooking pot. it’s also a term from casting to ‘pot’ something is to inset it into a frame work … JJ is the same as JIC it’s a representation of the sizing standards accordance ( like any object here has the 'CS ’ logo on becuse it’s met the canadian standards act compliance… ), however JJ/JIC it is important when buying wheels… I recevied this info awhile back buying wheels right from Japan, JJ/JIC and north american SAE / UR are different sizing specs! any wheel measuerd in japan , using JIC standards a wheel will always be a 1/2 narrower then when measured here. a JIC 9" wide wheel is apparently ( I got this from two different sources at two different shops I use to mount tyres and saw the measurments myself) a 9" wide JIC = 9.5" SAE made in north america… Weather it’s right or just a mis imprint on my $3000 wheels … i don’t know but I measered them myself… the differenc eis WHERE they are measered on the rim … ---
**Author:** ![Gonad](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/gonad/32/5481_2.png) [@Gonad](https://forums.speedlife.net/u/Gonad)\ **Post date:** [February 13, 2005, 8:41am UTC](https://forums.speedlife.net/t/car-terminology-someone-englighten-me/83631/7 "2005-02-13T08:41:12Z")
I assumed the POT was because the pistons were hollow cups that looked like cooking cups. I guess that’s probablly it. LOL, Iguess thee is no actual wording to those letters. Ok, cool…