# FD: Rule Book change on tire / weight

**URL:** <https://forums.speedlife.net/t/fd-rule-book-change-on-tire-weight/206130>\
**Category:** SON240sx Automotive\
**Created:** [November 16, 2010, 7:46pm UTC](https://forums.speedlife.net/t/fd-rule-book-change-on-tire-weight/206130 "2010-11-16T19:46:20Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![bing](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/bing/32/7211_2.png) [@bing](https://forums.speedlife.net/u/bing)\
**Post date:** [November 16, 2010, 7:46pm UTC](https://forums.speedlife.net/t/fd-rule-book-change-on-tire-weight/206130/1 "2010-11-16T19:46:20Z")

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[Wrecked](http://www.wreckedmagazine.com/blog/2010/11/15/new-weighttire-size-regulations-for-formula-drift-2011)

> **9.1**  
> **TIRE SIZE REGULATION**  
> Cars are limited to the size of the rear tire that can be used, depending on the weight  
> of the vehicle. There are 7 weight classes, each spanning 200 lbs. A car must be  
> track-ready, and running when it is weighed and registered to a weight class. A car will  
> be weighed without the driver, and once the car is registered to a weight class, it will  
> be recorded, and issued a class-specific sticker that must be displayed prominently on  
> the windshield. A car’s weight may fluctuate within the limits of it’s weight class, but it  
> can never weigh less than the minimum weight for its’ registered class. Tire sizes are  
> AS MEASURED in mm, across the span of the contact patch. Tires will be measured  
> on the rim, while on the car, while the car is on the ground. Tire size must not exceed  
> the maximum size dictated by class at any time on track. Tire size will be measured  
> and verified on track before the start of every tandem round. A Formula D official may  
> also check tire size at any time during the event.

> **Weight and Tire Classes-**  
> 2000-2199lbs up to 215mm tire width  
> 2200-2399lbs up to 235mm tire width  
> 2400-2599lbs up to 255mm tire width  
> 2600-2799lbs up to 275mm tire width  
> 2800-2999lbs up to 295mm tire width  
> 3000-3199lbs up to 315mm tire width  
> 3200-3399lbs up to 335mm tire width

I’d like to know who runs a 2100lbs car with a 275+ tire and how much they hate this 🙂

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**Author:** ![MPD47](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/mpd47/32/7383_2.png) [@MPD47](https://forums.speedlife.net/u/MPD47)\
**Post date:** [November 16, 2010, 8:11pm UTC](https://forums.speedlife.net/t/fd-rule-book-change-on-tire-weight/206130/2 "2010-11-16T20:11:52Z")

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The “Dmac” rule. I like it, but then my car already fits those rules. It’s really only going to effect the ridiculously big budget builds where every panel is carbon and half the car is tube chassis. Hell even Matt’s Z is tube in the rear with fiberglass bumpers/hatch and it meets these regs.

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**Author:** ![Theo23](https://avatars.discourse-cdn.com/v4/letter/t/43a26b/32.png) [@Theo23](https://forums.speedlife.net/u/Theo23)\
**Post date:** [November 16, 2010, 10:20pm UTC](https://forums.speedlife.net/t/fd-rule-book-change-on-tire-weight/206130/3 "2010-11-16T22:20:58Z")

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I’m sure the big guns like JR, Hubinette, Foust etc will not like this. I’m sure their cars weigh less than 2800lbs and wore larger than 275’s last season.

I also have heard a bunch of guys will be running different engines next year, is there a rule change as far as power plants go as well? ie: JR, Foust, and Dai mentioned it.