SFI 16.1 vs 16.5 Harness: Which One Do I Need?

First, what is SFI?

The SFI Foundation, Inc. (SFI) is a non-profit organization established to issue and administer standards for the quality assurance of specialty performance and racing equipment. They have served the automotive aftermarket and the motorsports industry since 1978.

What do I need to know?

Various off-road races and racing bodies have different rules as to what they require for harnesses. Most require either SFI 16.1 or 16.5 certified restraints. What’s the difference? Put simply: the faster your vehicle is traveling, the more strength a belt requires in a crash. While 16.1 covers the basics, 16.5 goes a little further.

SFI 16.1

SFI 16.1 certified 5.3 Harness

The most common required certification is SFI 16.1. Generally, when your race sanction says they require an SFI approved belt, this rating will do the job. When certifying for 16.1, SFI applies a load over a body block of 5,750lbs each on the laps and shoulders and over the complete 5 or 6 point assembly. The harness must not break under 6,300lbs for lap and shoulders belts, and 1,500lbs for anti-submarine straps. SFI labels should be placed on the left shoulder belt, left lap belt, and sub strap.

SFI 16.5


Some off-road sanctions are now requiring or recommending belts with higher breaking strength. This would be SFI 16.5. When certifying for 16.5, SFI applies a load over the body block of 11,000lbs over the complete 5 or 6 point assembly. The harnesses must not break under 7,000lbs for lap, shoulder, and anti-submarine straps. Additional tests are also run, including a roller adjuster micro-slip test and a webbing abrasion test. SFI labels should be placed on each shoulder belt, lap belt, and anti-submarine strap. Re-webbing is not permitted. This rating is mandated by NASCAR Truck Series, NHRA Top Fuel, and Funny Car. NASCAR leads the way in safety research and training so it’s wise to take their recommendation.

16.1 is widely adopted by manufacturers in the racing community. 16.5 is rated higher strength and has additional requirements. Depending on your race series, some will require 3” belts to be 16.1 certified, and 2” belts to be 16.5 certified. They want the higher rating to show that the 2” can withstand additional stress.

SFI actually has an additional certification for Youth Harnesses (16.2). It is not as well known and not manufactured as widely. The 16.2 minimum strength requirements are rated lower than 16.1’s (kids are usually racing at lower speeds), so most people just use the more widely available 16.1 harnesses.

What do you race?

SCORE- CR 34 Safety Harness: All vehicles except motorcycles and quads must have must have a heavy-duty type 5 point fast release (no push button or quick release type) seat belt and shoulder harness with metal to metal buckles and connectors for each occupant… The five point system consist of a 3” seat belt, 2” anti-submarine belt, and two 3” shoulder straps…All belts must be changed after three (3) years after the date of manufacture. SCORE recommends all belts be changed after one (1) year of use.

SNORE- SCR34– Safety Harness All vehicles must have 3-inch heavy duty type five point fast release (no push button or knob type) must be a lever type seat belt and shoulder harness with metal to metal buckles and connectors for each occupant… All belts must show manufacturer’s name, month and year of manufacture and must be readable or they have to be replaced. All belts must be changed after three years of date. 2-inch shoulder harness is allowed only if you are using an approved head and neck restraint.

ULTRA 4- 8.2.1– The driver restraint system shall consist of at least one 2” wide anti- submarine strap, one 2” wide lap belt and two 2” wide shoulder straps. Sternum straps and chest buckles may be used. 3” Lap Belts must meet or exceed SFI 16.1 Specifications. 2” Lap Belts must meet or exceed SFI 16.5 Specifications. Shoulder Belts must meet or exceed SFI 16.5 Specifications. All driver restraint systems must be replaced after three (3) years from the date of manufacture. It is highly recommended that all driver restraint systems be replaced after one year from the date of manufacture.

Best in the Desert- SCR35– All vehicles must have a minimum of five-point harnesses (six and seven point recommended) consisting of a lap belt, anti-sub strap belt, and two shoulder harnesses with metal to metal “latch and link” buckling style connectors at each point for every occupant in the race vehicle. No push button type or cam lock style releases will be permitted. The harness system shall bear the SFI Foundation’s 16.1 or 16.5 manufacturer’s certification label on each webbing component. The five-point (or six or seven points) harness system shall consist of one anti-submarine strap measuring a minimum of 1.75-inch wide, one 3-inch wide lap belt, and two 3-inch wide shoulder harnesses (no “Y” type shoulder belts are permitted). Full 2-inch, 2-inch to 3-inch transitional, and 3-inch folded and sewn to 2-inch shoulder belts are permitted only when used in conjunction with a frontal head restraint device (FHR). The FHR must be presented at technical inspection if any of the listed variations of the 2-inch shoulder harnesses are used. Two-inch all over safety harnesses (complete 2-inch all over webbing) will be permitted by Best in the Desert only if bearing the SFI 16.5 manufacturer’s certification label on all webbing components.

-3 inch needs at least 16.1, all 2-inch variants need 16.5 and frontal head restraint (FHR)-

WORCS- SXS 12 2” wide, 5 (five) point restraint system for both driver and occupant are required. The 5 (five) point system must include an anti-submarine belt that is at least 2” wide.

SRT8 UP SXS Series
9-13 JUNIOR, 900 and 1000/TURBO PRODUCTION
-All participants must wear a seatbelt (4 point harness is highly recommended)
PRO Bounty
-3” 4 point harness in vehicles with OEM chassis and 3” 5 points in vehicles with custom build chassis.

M.O.R.E – The single anti-submarine strap of the five point system shall be attached to the floor structure as close to the front as practical so that it will exert maximum restraint to the upward movement of the belt and harness. All belts must show manufacturer’s name, month and year of manufacture and must be readable or they have to be replaced. All belts must be changed after three years of date. 2-inch shoulder harness is allowed only if you are using an approved head and neck restraint.

Lucas Oil Off-Road Raving Series (LOORRS)- SR6 – A quick release lap belt not less than three inches wide is required. A 2-inch belt may be used provided it is certified to SFI spec 16.5. Cam Lock type belts are not allowed….. Shoulder harnesses are mandatory. Harnesses must be no less than three inches wide and must come from behind driver’s seat. 2-inch harnesses may be used provided they are certified to SFI spec 16.5…..Seat belts must be certified to SFI specs 16.1 or 16.5 and dated by the manufacturer. Belts must not be used beyond two years after stated date.

GNCC- UTV D.2.A– Four-point harness restraints, securely fastened on both occupants at all times.

Southern Rock Racing Series (SRRS) 5pt. harness is the minimum requirement for seat belts.

PURE Off Road Desert Series- 12.9.11– All vehicles must have a five-way, five-point H-style driver restraint system for each occupant. Driver restraints must incorporate a lap belt, anti-submarine strap, and shoulder straps. The driver restraint system shall consist of one 2” wide anti-submarine strap, one 2” wide lap belt and two 2” wide shoulder straps. Sternum straps and chest buckles may be used.

Did we miss your sanction? Leave a comment and we’ll add it to the list.

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