BoP Lab / Classes / STU

STU vs F5 vs P2 pace at every track

Lap times across years say as much about the weather as the class. % of STU is each class's best lap as a share of STU's on the same day, so the conditions drop out: 100% is level, less is quicker, and a move in it is the class getting faster or slower against the field.

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AS +B-Spec +EP +vsF5 ×FA +FC +FE2 +FF +FP +FV +FX +GT1 +GT2 +GTX +HP +P +vsP2 ×SM +SMX +SRF3 +STL +STU×T1 +T2 +T3 +T4 +Show 50 inactive classes

Series Runoffs Super Tour Both

Reference · what % is measured against

Tracks · untick to narrow Auto Club Speedway Barber Motorsports Park Blackhawk Farms Raceway Buttonwillow Raceway Park Circuit of St. Louis (formerly Gateway Motorsports Circuit of the Americas Daytona International Speedway Grattan Raceway Hallett Motor Racing Circuit Homestead-Miami Speedway Indianapolis Motor Speedway Laguna Seca Michelin Raceway Road Atlanta Mid-Ohio Sports Car Course New Jersey Motorsports Park NOLA Motorsports Park Pacific Raceways Pittsburgh International Race Complex Portland International Raceway Pueblo Motorsports Park Road America Sebring International Raceway Sonoma Raceway Summit Point Raceway Thunderhill Raceway Park Virginia International Raceway Watkins Glen International Willow Springs Raceway World Wide Technology Raceway

Closest to the field: STU 100.0% of STU Eric Heinrich, Daytona International Speedway Runoffs 2015 race · F5 93.1% of STU Sven de Vries, Virginia International Raceway Runoffs 2022 race · P2 84.3% of STU Jeff Shafer, Indianapolis Motor Speedway Runoffs 2017 qualifying

% of STULap times

STUF5P2solid race · dashed qualifying · slower is lower

STUF5P2solid race · dashed qualifying · each class's best lap as a share of STU's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker

	Event	STU			F5					P2
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs STU	% of STU	Qual best	Race best	Trap	vs STU	% of STU
	Road America Runoffs 20262026-09-28	2:24.912Richard Astacio · fastest of 17 · top 5 within 2.6s+1.829s (+1.28%)	2:26.416Richard Astacio · fastest of 16 · top 5 within 1.5s+1.919s (+1.33%)	145.1Hugh Stewart+0.8 mph (+0.5%)						2:10.606Greg Gyann · fastest of 11 · top 5 within 5.3s+3.201s (+2.51%)	2:09.441Mike Reupert · fastest of 11 · top 5 within 4.2s+1.119s (+0.87%)	155.0Matt Strand+2.4 mph (+1.6%)	-16.975squal -14.306s	88.4%qual 90.1%
15 rule changes (STU: 15)7 weight · 4 induction · 3 tyres & wheels · 1 engineshowhide 2026-09-01 STU Wheel and tire requirements for GT3U #40679tyres & wheels 2026-07-01 STU 9” Wheels #40433tyres & wheels 2026-07-01 STU Weight adjustment to former GT3U cars #40474weight 2026-06-01 STU Request to allow BMW M50B20TU engine in STU #40202engine 2026-06-01 STU Calculating Weight #40224weight 2026-05-01 STU Turbo Restrictor Size Increase Request #40008induction 2026-05-01 STU GT86 Cups Car in STU #40028weight 2026-04-01 STU Mazda Rx-8 Renesis - Streetported Variant & Added Weight #39785weight 2026-04-01 STU Eliminate 33 and 34 mm TIRs #39872weight 2026-03-01 STU Fab 9 Racing Intake Manifold in STU #39767induction 2026-01-01 STU Request for Permission on Aftermarket Turbo Kit and Intake #39529induction 2025-12-01 STU Turbo Inlet Restrictor Table #38961induction 2025-12-01 STU 275 Tire Rule #38983tyres & wheels 2025-12-01 STU STU Honda Engine weight penalty #39375weight 2025-11-01 STU Non-Homologated Engine Swaps - Specifically K24A2 w/ Honda CRZ #38746weight
	Road America Runoffs 20252025-09-29	2:23.083Peter Cunningham · fastest of 16 · top 5 within 2.6s-3.144s (-2.15%)	2:24.497Chip Herr · fastest of 15 · top 5 within 3.8s-1.327s (-0.91%)	144.3Chip Herr-1.0 mph (-0.7%)
19 rule changes (STU: 18, P2: 1)8 weight · 3 engine · 3 tyres & wheels · 1 cars added · 1 induction · 1 wording · 2 othershowhide 2025-09-01 STU Lotus Weight Reduction E&O #38919weight 2025-08-01 STU STU-TCR Adjustments #38723weight 2025-08-01 STU Lotus Weight Reduction #38772weight -50 lbs 2025-07-01 STU 2.8-3.2L N/A Engine Allowances #38007engine 2025-07-01 STU 2006-2015 Mazda Miata Intake Manifold #38422induction 2025-07-01 STU Requesting Approval of the JDM Honda h23a #38489cars added 2025-05-01 STU Wheel Size Inconsistency #38018tyres & wheels 2025-05-01 STU Table C: STU-GT3U Clarification #38268weight 2025-03-01 STU BMW N54/N55 Engine Allowance Follow Up #37447engine 2025-03-01 STU STU Mini Cooper pulley size clarification re: letter #36980 #37717wording 2025-03-01 STU Question About a Weight Modifier #37782weight 2025-03-01 STU Increase Minimum Weight #37919weight +100 lbs 2025-01-01 STU Audi 1.8t Wagon STU Table B #36685weight 2025-01-01 STU Merger GT3 to STU #37486other 2025-01-01 STU GT3 TCR Tire allowance #37494tyres & wheels 2024-12-01 P2 2000 cc Pinto Engine Car Weight #37187weight 2024-12-01 STU Request to Remove Miata Hubs from General category #37138tyres & wheels 2024-12-01 STU BMW N54/N55 Engine Allowance #37146engine 2024-11-01 STU R53 15% Pulley Request #36980other
	Road America Runoffs 20242024-10-01	2:26.227Thomas Noble · fastest of 18 · top 5 within 2.3s-1.656s (-1.12%)	2:25.824Thomas Noble · fastest of 17 · top 5 within 2.4s-2.586s (-1.74%)	145.3Thomas Noble+1.1 mph (+0.8%)						2:07.405Bart Wolf · fastest of 14 · top 5 within 3.0s-1.109s (-0.86%)	2:08.322Bart Wolf · fastest of 13 · top 5 within 0.6s-1.471s (-1.13%)	152.5Lucian Pancea-0.6 mph (-0.4%)	-17.502squal -18.822s	88.0%qual 87.1%
9 rule changes (STU: 4, P2: 5)4 engine · 1 induction · 1 tyres & wheels · 1 weight · 2 othershowhide 2024-08-01 STU RWD Turbo Disadvantage #36255induction 2024-05-01 P2 CN Spec ECU #35835engine 2024-05-01 P2 E&O - Correct FIA Group CN spec line notes #35900tyres & wheels 2024-03-01 STU Letter #35397 addendum #35453weight 2024-03-01 STU S54 Drysump #35464other 2024-02-01 STU ST Electric-Assisted Steering Systems #35066other 2024-01-01 P2 E&O - Clarify B.1 modified engine range in AMAC spec lines #35225engine 2024-01-01 P2 Replacement Engine Crankcase for 07/08 Suzuki GSX-R1000 Engines #35340engine 2023-12-01 P2 Correct Table 1 for Engine Date Range Specifications #35182engine
	Virginia International Raceway Runoffs 20232023-09-23	2:00.389Johan Schwartz · fastest of 13 · top 5 within 2.3s-0.226s (-0.19%)	2:02.302Mark Liller · fastest of 14 · top 5 within 1.6s-30.055s (-19.73%)	144.0Mark Liller+0.1 mph (+0.1%)						1:48.590Greg Gyann · fastest of 12 · top 5 within 1.7s+1.024s (+0.95%)	1:48.829Lucian Pancea · fastest of 11 · top 5 within 0.9s-27.005s (-19.88%)	150.9Lucian Pancea-0.2 mph (-0.2%)	-13.473squal -11.799s	89.0%qual 90.2%
11 rule changes (STU: 3, P2: 8)4 weight · 2 cars added · 2 engine · 1 induction · 1 tyres & wheels · 1 wordingshowhide 2023-07-01 STU 2022 Toyota GR Cup for STU #34449cars added 2023-05-01 P2 Clarify minimum side body height requirement #34143tyres & wheels 2023-05-01 P2 Clarify closed cockpit single seat car allowance #34144wording 2023-04-01 P2 Remove redundant effective date language and update engine table #34012engine 2023-04-01 P2 E&O - Correct dimensional equivalents #34038weight 2023-04-01 STU Alternate OEM Miata Intake Manifold #33827induction 2023-03-01 STU E&O STU NA Weight Chart. #33737weight 2023-01-01 P2 Request to Classify Sebeco NP01 #33378cars added 2023-01-01 P2 Radical spec line clarifications #33485weight 2023-01-01 P2 E&O original class intent #33519weight 2023-01-01 P2 Update Engine Table Spec Line B.1 #33608engine
	Virginia International Raceway Runoffs 20222022-09-24	2:00.615Johan Schwartz · fastest of 21 · top 5 within 2.6s+0.667s (+0.56%)	2:32.357Mark Liller · fastest of 19 · top 5 within 4.3s+31.874s (+26.46%)	143.9Johan Schwartz+0.1 mph (+0.1%)	1:57.689James Weida · fastest of 11 · top 5 within 3.9s+0.328s (+0.28%)	2:21.862Sven de Vries · fastest of 10 · top 5 within 14.3s+24.290s (+20.66%)	142.9Calvin Stewart+0.1 mph (+0.1%)	-10.495squal -2.926s	93.1%qual 97.6%	1:47.566Tim Day Jr · fastest of 12 · top 5 within 3.0s-1.545s (-1.42%)	2:15.834Greg Gyann · fastest of 12 · top 5 within 10.1s+25.576s (+23.20%)	151.1Robert Iversen+1.8 mph (+1.2%)	-16.523squal -13.049s	89.2%qual 89.2%
37 rule changes (STU: 21, F5: 6, P2: 10)9 weight · 8 engine · 4 induction · 4 tyres & wheels · 2 aero · 2 cars added · 1 wording · 7 othershowhide 2022-09-01 F5 Intake Boots Correction #33028induction 2022-08-01 F5 Ensure availability of ECU for Rotax engines #32695engine 2022-08-01 STU Request Mazda 13 B turbo #32668induction 2022-08-01 STU Hood Vents and Intercooler Scoops #32733other 2022-08-01 STU Non 4 valve weight reduction removed #32808weight 2022-07-01 F5 Clarify stepped exhaust header references #32743engine 2022-07-01 STU Error in new minimum weight table when combined with other text #32711weight 2022-07-01 STU Redundant Language in May GCR #32713engine 2022-06-01 F5 593 carb boot availability and oil pump clarification #32527induction 2022-05-01 P2 E&O Clarification of Chassis Construction Requirements #32469tyres & wheels 2022-05-01 P2 Clean up P2 wording #32525wording 2022-05-01 STU Opposed to the Proposed STU Weight Chart #32381weight 2022-05-01 STU Clarification request for GCR 9.1.4.D.3.a Splitter Definition #32414aero 2022-04-01 P2 After Market to Aftermarket #32373other 2022-04-01 STU Request Adjustment to Min Weight for STU BMW E36 M3 (95-99) #31535weight -90 lbs 2022-04-01 STU BMW E36 M3 Canadian (North American) S50B32 engine #31866engine 2022-04-01 STU Engine Swap Origin Country #32209engine 2022-04-01 STU CRX/Civic Del Sol #32214cars added 2022-04-01 STU Error correction #32383weight 2022-04-01 STU Single TB Weight Modifiers Add to Chart #32393weight 2022-03-01 F5 E&O class name #32194other 2022-03-01 P2 Add spec line for Beasley B2 #32147weight 2022-03-01 P2 E&O Table 1 spec line wing terminology #32148aero 2022-03-01 P2 E&O class name #32196other 2022-03-01 STU Single TB Weight Modifiers #31449weight 2022-03-01 STU Request to Remove A4 1.8t from STU Spec Line Tables #31465weight 2022-03-01 STU Improved Touring Tires #32063tyres & wheels 2022-02-01 P2 E&O Engine section #31969engine 2022-02-01 STU Request Allowance for Balance Shaft Delete in STU #31434engine 2022-02-01 STU Request Louvers in hood vents #31916other 2022-01-01 F5 Data Box Mounting Plate #31638other 2022-01-01 P2 E&O letter #31539 – Control Area definition #31783tyres & wheels 2022-01-01 STU Request to Add Honda K23 Spec Line #30682cars added 2022-01-01 STU RE: Aug FT letter 30682 #31060other 2022-01-01 STU Throttling Device Clarification #31323induction 2021-12-01 P2 BoP adjustment effective 1-1-22 #31538engine 2021-12-01 P2 E&O clarification of "Control Area" definition #31539tyres & wheels
	Indianapolis Motor Speedway Runoffs 20212021-09-25	1:47.078Joe Moser · fastest of 30 · top 5 within 2.0s-1.843s (-1.69%)	1:47.441Joe Moser · fastest of 28 · top 5 within 1.8s-1.946s (-1.78%)	146.9Kip VanSteenburg	1:42.619Ryan Mayfield · fastest of 22 · top 5 within 1.6s-0.517s (-0.50%)	1:43.140Sven de Vries · fastest of 20 · top 5 within 1.7s+0.280s (+0.27%)	144.4James Weida	-4.301squal -4.459s	96.0%qual 95.8%	1:33.235Tim Day Jr · fastest of 16 · top 5 within 3.3s+1.409s (+1.53%)	1:35.322Tim Day Jr · fastest of 10 · top 5 within 4.8s+2.841s (+3.07%)	150.3Robert Iversen	-12.119squal -13.843s	88.7%qual 87.1%
23 rule changes (STU: 12, F5: 3, P2: 8)5 engine · 4 tyres & wheels · 4 weight · 1 aero · 1 cars added · 1 induction · 1 suspension & brakes · 2 wording · 4 othershowhide 2021-09-01 P2 P2 CN Engine Rebuild Clarification #31000engine 2021-08-01 F5 Clarify allowable assisted shifting systems #30871wording 2021-08-01 F5 Request to correct terminology #30976tyres & wheels 2021-08-01 P2 F5 P2 Conversion #30856other 2021-08-01 P2 Clarify minimum body width requirement #30859tyres & wheels 2021-07-01 STU STU Fender flares #30696tyres & wheels 2021-07-01 STU Request weight reduction for 12A bridgeport motor in Miata #30751weight -200 lbs 2021-06-01 F5 Request to Allow Rotax 593 HO Engine #30712engine 2021-05-01 P2 E&O tonneau cover provision in cockpit opening section #30459other 2021-05-01 P2 Remove effective dates in Table 1 #30468other 2021-05-01 P2 E&O Maximum Valves Per Cylinder #30560engine 2021-05-01 STU Request for Fender Flare Clarification #30375weight 2021-04-01 STU Provision for Interchangeable Engine Components Already Allowed #30342engine 2021-04-01 STU ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wording 2021-03-01 P2 Add a new spec line for a 2-cycle, 3-cylinder engine up to 820cc #30272engine 2021-03-01 STU Super Touring Alternate Miata Hubs #30345tyres & wheels 2021-02-01 STU Brake Component Relocation #29990suspension & brakes 2021-02-01 STU Porsche PDK #30081weight 2021-02-01 STU Reference Letter #29333 Proposed STU 13B Spec Line Changes #30086weight 2021-02-01 STU Drive Shaft Request #30087other 2021-01-01 STU 13B Rules Adjustment #29333cars added 2020-12-01 P2 Balance of Performance adjustments effective 01-01-2021 #29822induction 2020-12-01 STU Request clarification on wing measurement #29640aero
	Road America Runoffs 20202020-10-02	2:27.883David Fiorelli · fastest of 14 · top 5 within 4.1s	2:28.410Anthony Geraci · fastest of 14 · top 5 within 3.1s	144.2David Fiorelli	2:20.954Calvin Stewart · fastest of 16 · top 5 within 1.8s	2:21.391James Weida · fastest of 14 · top 5 within 1.5s	143.2Aaron Ellis	-7.019squal -6.929s	95.3%qual 95.3%	2:08.514Robert Iversen · fastest of 12 · top 5 within 3.0s	2:09.793Robert Iversen · fastest of 12 · top 5 within 3.9s	153.1Robert Iversen	-18.617squal -19.369s	87.5%qual 86.9%
29 rule changes (STU: 17, F5: 6, P2: 6)9 induction · 7 engine · 5 weight · 3 aero · 1 cars added · 4 othershowhide 2020-10-01 F5 Request to Update Suzuki Engine Years for F500 #29453engine 2020-09-01 P2 E&O clarification of P2 rear wing requirements #29205aero 2020-09-01 STU Request for Advanced Aero Rule Wording Clarification. #29124aero 2020-08-01 STU Minimum Weight Determination #27695weight 2020-08-01 STU ST Gurney flap Wicker clarification #29012aero 2020-07-01 F5 Request for Cockpit Adjustment of External Jetting Devices #28359other 2020-07-01 F5 Two Stroke Motors (reply to #28359 WDYT) #28816engine 2020-07-01 F5 Re letter requesting driver adjustable carb mixture #28840other 2020-07-01 F5 #28359 WDYT Request for Cockpit Adjustment #28875other 2020-07-01 STU Request for Alternate Intake Manifold #26514induction 2020-07-01 STU Request for Addition to GT3 Approved Turbo List #27576induction 2020-07-01 STU Request BoP for my Car #29004induction 2020-07-01 STU Sequential Shifters in STU #29031other 2020-06-01 P2 Classify Elan NP01 in P2 Table 1 #28812cars added 2020-06-01 STU Rotary Help #27833weight 2020-05-01 P2 SCCA Enterprises ESR / P2 engine restrictor testing #28669induction 2020-04-01 P2 Add ESR inlet restrictor #27869induction 2020-04-01 STU Request to approve Honda S2000 HKS supercharger #27281engine 2020-04-01 STU Request BoP on the Lotus #27637weight +100 lbs 2020-04-01 STU Turbo Inlet Restrictor On MK5 Volkswagen #27704induction 2020-04-01 STU Honda K20C1 removal #27732induction 2020-04-01 STU Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engine 2020-04-01 STU Alternate Engine for Porsche 944 #28259engine 2020-03-01 P2 Request for Fly by Wire Rule Wording Change #28247engine 2020-03-01 STU Please Modify the STU Wheel Size Rule for Clarity #27694weight 2020-03-01 STU Turbo Engine Cars Base Weight #28032weight 2020-01-01 F5 Change 600cc restrictor size #27883induction 2020-01-01 P2 Request for addition of BMW Engine in P2 Engine Table #27821engine 2019-12-01 STU Request for an electronic throttle body #27342induction
	Virginia International Raceway Runoffs 20192019-10-05	1:59.948Kevin Boehm · fastest of 25 · top 5 within 3.5s	2:00.483Kevin Boehm · fastest of 25 · top 5 within 2.5s	143.8Kevin Boehm	1:57.361Wiley Mcmahan · fastest of 15 · top 5 within 3.8s	1:57.572Wiley Mcmahan · fastest of 15 · top 5 within 4.0s	142.8Eric McRee	-2.911squal -2.587s	97.6%qual 97.8%	1:49.111Robert Iversen · fastest of 14 · top 5 within 0.8s	1:50.258Greg Gyann · fastest of 13 · top 5 within 0.4s	149.4Robert Iversen	-10.225squal -10.837s	91.5%qual 91.0%
32 rule changes (STU: 22, F5: 1, P2: 9)8 induction · 8 weight · 5 engine · 3 aero · 3 cars added · 2 suspension & brakes · 2 tyres & wheels · 1 wordingshowhide 2019-10-01 P2 Update Engine Table Line E notes #27414engine 2019-08-31 F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbs 2019-08-31 P2 Update P2 Engine Table spec lines to reflect 3/1/2019 #27254engine 2019-08-31 STU Request to correct E&O advanced aerodynamics #27290aero 2019-07-01 P2 E&O Transmissions #27006tyres & wheels 2019-07-01 STU Remove -2mm penalty from SR20DET Nissan #26982weight 2019-07-01 STU Request clarification for manifold and throttle in STU #27004induction 2019-06-01 P2 Request to restrict all cars #26246weight 2019-05-31 STU Request to clarify afterrmarket side skirts exhaust exit #26814suspension & brakes 2019-05-31 STU Wheel Flare wording #26872tyres & wheels 2019-05-01 STU Request Ride Height Clarification #26597suspension & brakes 2019-04-01 STU Request to Use Japanese Mazda 13b Intake Manifold #25790induction 2019-04-01 STU Request Alternate Intake for Mazda MZR In a Rear Wheel Drive App. #26352induction 2019-04-01 STU E&O Suspension #26424wording 2019-04-01 STU Revisit B20 VTEC #26530cars added 2019-04-01 STU Move Flared Fenders to STU Advanced Aero #26564aero 2019-04-01 STU TCA Civic SI E&O #26606induction 2019-04-01 STU S54 Spec line #26620weight 2019-03-01 P2 Change Engine Table Lines B.1 & B.5 #25777engine 2019-03-01 P2 Change Line A.1 restrictor size #26429induction 2019-03-01 STU Request to Class Assignment for 2017 Civic #24287cars added 2019-03-01 STU Request to run E46 3246cc in STU #25126weight 2019-03-01 STU Engine Classification for Rotary #25564engine 2019-03-01 STU K24/K20 Head Swap Clarification/Amendment #25899induction 2019-03-01 STU Request to Classify 12a Bridge Ported Rotary Engine #25985cars added 2019-03-01 STU World Challenge Car Eligibility #26387weight 2019-03-01 STU Request a phone call for discussion regarding weight #26398weight 2019-03-01 STU Advanced Aero E&O #26413aero 2019-01-01 P2 Request to Allow 1345cc Hayabusa Engines for Spec Line P2 Cars #25595engine 2019-01-01 P2 Change CN inlet restrictor implementation date #25816induction 2019-01-01 P2 Clarify Honda K20A-FD2 parts requirement #25950weight 2019-01-01 STU Request to Equalize Direct Injected Turbo Cars #24890induction
	Sonoma Raceway Runoffs 20182018-10-10	1:19.234Franklin Church · fastest of 10 · top 5 within 21.5s	1:46.514Kevin Boehm · fastest of 9 · top 5 within 7.4s	103.0Franklin Church	1:41.807Jeff Jorgenson · fastest of 5 · top 5 within 6.6s	1:42.491David Lapham · fastest of 5 · top 5 within 9.5s	113.3David Lapham	-4.023squal +22.573s	96.2%qual 128.5%	1:28.784Tim Day Jr · fastest of 17 · top 5 within 5.0s	1:32.071Chuck Bona · fastest of 18 · top 5 within 0.9s	144.4Tim Day Jr	-14.443squal +9.550s	86.4%qual 112.1%
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25	1:48.921Rob Huffmaster · fastest of 34 · top 5 within 2.0s	1:49.387Rob Huffmaster · fastest of 31 · top 5 within 2.4s		1:43.136Wiley Clinton McMahan · fastest of 38 · top 5 within 1.4s	1:42.860Wiley Clinton McMahan · fastest of 37 · top 5 within 1.6s		-6.527squal -5.785s	94.0%qual 94.7%	1:31.826Jeff Shafer · fastest of 26 · top 5 within 4.9s	1:32.481Jeff Shafer · fastest of 24 · top 5 within 3.8s		-16.906squal -17.095s	84.5%qual 84.3%
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19	1:32.738Joe Moser · fastest of 16 · top 5 within 2.5s	1:34.597Cameron Maugeri · fastest of 16 · top 5 within 0.8s		1:28.528Calvin Stewart · fastest of 14 · top 5 within 3.9s	1:29.853Steven Thompson · fastest of 12 · top 5 within 4.5s		-4.744squal -4.210s	95.0%qual 95.5%	1:20.188Jeff Shafer · fastest of 18 · top 5 within 4.0s	1:20.904Jeff Shafer · fastest of 16 · top 5 within 2.2s		-13.693squal -12.550s	85.5%qual 86.5%
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21	2:05.494Eric Heinrich · fastest of 18 · top 5 within 4.6s	2:06.756Eric Heinrich · fastest of 17 · top 5 within 3.5s		2:01.824W. Clint McMahan · fastest of 16 · top 5 within 3.0s	2:03.298Matthew Strand · fastest of 15 · top 5 within 4.9s		-3.458squal -3.670s	97.3%qual 97.1%	1:51.825Chris Farrell · fastest of 17 · top 5 within 3.6s	1:52.355Jeff Shafer · fastest of 17 · top 5 within 2.8s		-14.401squal -13.669s	88.6%qual 89.1%

By track

Track	Events	Typical % of STU	Best	Latest
Road America	4	100.0%	100.0%Runoffs 2020	100.0%Runoffs 2026
Virginia International Raceway	3	100.0%	100.0%Runoffs 2019	100.0%Runoffs 2023
Indianapolis Motor Speedway	2	100.0%	100.0%Runoffs 2017	100.0%Runoffs 2021
Daytona International Speedway	1	100.0%	100.0%Runoffs 2015	100.0%Runoffs 2015
Mid-Ohio Sports Car Course	1	100.0%	100.0%Runoffs 2016	100.0%Runoffs 2016
Sonoma Raceway	1	100.0%	100.0%Runoffs 2018	100.0%Runoffs 2018

About this data

Every event the class ran, at any track, oldest to newest on the chart and newest first in the table. Each point is the class's best lap as a share of STU's best on the same day: the weather and the day cancel out, so one figure compares across years where lap times cannot; a class that suits one track more than another still reads differently there. It still moves when the yardstick's own balance changes or its field thins, and an event the yardstick did not run has no point. A best from fewer than three cars is greyed. The rule changes that took effect between two events are folded between their rows.