BoP Lab / Classes / STL

STL vs FE2 vs F5 pace at every track

Lap times across years say as much about the weather as the class. % of STL is each class's best lap as a share of STL'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 +vsFE2 ×FF +FP +FV +FX +GT1 +GT2 +GTX +HP +P +P2 +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: STL 100.0% of STL Kevin Boehm, Daytona International Speedway Runoffs 2015 race · FE2 78.8% of STL Max Grau, Indianapolis Motor Speedway Runoffs 2021 race · F5 84.1% of STL Sven de Vries, Indianapolis Motor Speedway Runoffs 2021 race

% of STLLap times

STLFE2F5solid race · dashed qualifying · slower is lower

STLFE2F5solid race · dashed qualifying · each class's best lap as a share of STL's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker

	Event	STL			FE2					F5
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs STL	% of STL	Qual best	Race best	Trap	vs STL	% of STL
	Road America Runoffs 20262026-09-28	2:30.537Derek Ketchie · fastest of 16 · top 5 within 2.9s-1.528s (-1.00%)	2:30.657Danny Steyn · fastest of 16 · top 5 within 0.6s-1.470s (-0.97%)	134.8Mike Taylor+2.6 mph (+2.0%)	2:12.326Franklin Futrelle · fastest of 8 · top 5 within 1.9s-0.149s (-0.11%)	2:11.881Franklin Futrelle · fastest of 8 · top 5 within 1.6s-1.458s (-1.09%)	143.5Steve Whitston-5.5 mph (-3.7%)	-18.776squal -18.211s	87.5%qual 87.9%
5 rule changes (STL: 4, FE2: 1)3 weight · 1 removed · 1 othershowhide 2026-07-01 STL Spec Line Clean Up #40344removed 2026-06-01 STL Calculating Weight #40224weight 2026-04-01 STL Classifications #39885weight 2026-01-01 STL Weight adjustment for STL #39579weight 2025-10-01 FE2 FE & FE2 Bubble Tail #38978other
	Road America Runoffs 20252025-09-29	2:32.065Jose Osiris Pena · fastest of 14 · top 5 within 3.4s+2.002s (+1.33%)	2:32.127Jose Osiris Pena · fastest of 13 · top 5 within 2.4s+1.882s (+1.25%)	132.2Jon Sewell-2.1 mph (-1.5%)	2:12.475Franklin Futrelle · fastest of 11 · top 5 within 1.4s+0.969s (+0.74%)	2:13.339Franklin Futrelle · fastest of 10 · top 5 within 0.6s+0.591s (+0.45%)	149.0Steve Whitston+3.7 mph (+2.6%)	-18.788squal -19.590s	87.6%qual 87.1%
4 rule changes (STL: 3, FE2: 1)2 weight · 1 tyres & wheels · 1 othershowhide 2025-08-01 STL Lotus Weight Reduction #38772weight -50 lbs 2025-05-01 STL E&O: SMX Allowance in STL #37945weight 2025-04-01 FE2 Driver Safety & Comfort #37965other 2024-12-01 STL Request to Remove Miata Hubs from General category #37138tyres & wheels
	Road America Runoffs 20242024-10-01	2:30.063Joe Moser · fastest of 18 · top 5 within 3.7s-1.357s (-0.90%)	2:30.245Joe Moser · fastest of 16 · top 5 within 4.2s-1.870s (-1.23%)	134.3Joe Moser+1.3 mph (+1.0%)	2:11.506Porter Aiken · fastest of 18 · top 5 within 0.5s-1.300s (-0.98%)	2:12.748Porter Aiken · fastest of 17 · top 5 within 2.0s-0.523s (-0.39%)	145.3Porter Aiken+1.9 mph (+1.3%)	-17.497squal -18.557s	88.4%qual 87.6%
4 rule changes (STL: 4)2 induction · 1 weight · 1 othershowhide 2024-02-01 STL ST Electric-Assisted Steering Systems #35066other 2024-02-01 STL BOP Adjustments #35112weight 2024-02-01 STL Mazda 12A #35320induction 2024-01-01 STL Alternate Carburetor Request for 79-85 RX7 12a #35181induction
	Virginia International Raceway Runoffs 20232023-09-23	2:05.779Danny Steyn · fastest of 22 · top 5 within 3.4s+0.305s (+0.24%)	2:06.682Joe Moser · fastest of 20 · top 5 within 1.5s-1.150s (-0.90%)	131.8Danny Steyn+0.1 mph (+0.1%)	1:50.665Charles Russell Turner · fastest of 26 · top 5 within 2.3s-0.188s (-0.17%)	1:51.098Franklin Futrelle · fastest of 19 · top 5 within 1.4s-20.947s (-15.86%)	141.3Franklin Futrelle-0.6 mph (-0.4%)	-15.584squal -15.114s	87.7%qual 88.0%
2 rule changes (STL: 2)2 tyres & wheelsshowhide 2023-06-01 STL Clarify STL table B - IT spec notes on Tires #34187tyres & wheels 2023-01-01 STL Spec MX5 in STL #33473tyres & wheels
	Virginia International Raceway Runoffs 20222022-09-24	2:05.474Danny Steyn · fastest of 24 · top 5 within 2.3s-1.729s (-1.36%)	2:07.832Danny Steyn · fastest of 22 · top 5 within 1.9s+0.559s (+0.44%)	131.7Trever Degioanni-3.2 mph (-2.3%)	1:50.853Charles Russell Turner · fastest of 25 · top 5 within 1.1s-0.209s (-0.19%)	2:12.045Jason Conzo · fastest of 22 · top 5 within 1.8s+19.891s (+17.74%)	141.9Eric Cruz-0.6 mph (-0.5%)	+4.213squal -14.621s	103.3%qual 88.3%	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%)	+14.030squal -7.785s	111.0%qual 93.8%
11 rule changes (STL: 5, F5: 6)4 induction · 2 engine · 1 tyres & wheels · 1 weight · 1 wording · 2 othershowhide 2022-09-01 F5 Intake Boots Correction #33028induction 2022-08-01 F5 Ensure availability of ECU for Rotax engines #32695engine 2022-07-01 F5 Clarify stepped exhaust header references #32743engine 2022-06-01 F5 593 carb boot availability and oil pump clarification #32527induction 2022-03-01 F5 E&O class name #32194other 2022-03-01 STL Single TB Weight Modifiers #31449weight 2022-03-01 STL Improved Touring Tires #32063tyres & wheels 2022-01-01 F5 Data Box Mounting Plate #31638other 2022-01-01 STL Throttling Device Clarification #31323induction 2022-01-01 STL Mazda Renesis Restriction #31467induction 2022-01-01 STL Clarification of 79-85 RX7 Spec line #31621wording
	Indianapolis Motor Speedway Runoffs 20212021-09-25	1:51.665Danny Steyn · fastest of 42 · top 5 within 1.7s-0.982s (-0.87%)	2:02.711Joe Moser · fastest of 37 · top 5 within 3.2s+10.122s (+8.99%)	131.8Max Gee	1:36.395Max Grau · fastest of 28 · top 5 within 0.7s	1:36.655Max Grau · fastest of 28 · top 5 within 0.7s	146.2Gray Fowler	-26.056squal -15.270s	78.8%qual 86.3%	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	-19.571squal -9.046s	84.1%qual 91.9%
18 rule changes (STL: 15, F5: 3)3 engine · 2 aero · 2 induction · 2 suspension & brakes · 2 tyres & wheels · 2 weight · 1 cars added · 2 wording · 2 othershowhide 2021-09-01 STL Request to clean up Spec MX-5 Redundancy #31069other 2021-08-01 F5 Clarify allowable assisted shifting systems #30871wording 2021-08-01 F5 Request to correct terminology #30976tyres & wheels 2021-06-01 F5 Request to Allow Rotax 593 HO Engine #30712engine 2021-06-01 STL VW Engine Request #30625engine 2021-05-01 STL Solstice Ride Height #30183suspension & brakes 2021-05-01 STL Request Mazda B5 DOHC #30420cars added 2021-05-01 STL Honda B16A (JDM) Restrictor change #30531induction 2021-04-01 STL ST Oil Coolers E&O Correction to 9.1.4.2.H #30388wording 2021-03-01 STL GM Ecotec engines in STL #30247engine 2021-03-01 STL Super Touring Alternate Miata Hubs #30345tyres & wheels 2021-02-01 STL Brake Component Relocation #29990suspension & brakes 2021-02-01 STL Super Touring Wing Clarification #30111aero 2021-02-01 STL Transmission Options #30118other 2021-01-01 STL Request for FWD and RWD Parity #29728weight 2021-01-01 STL Request to Remove Honda F20C 2% Weight Penalty #29815weight 2021-01-01 STL Request for FWD and RWD Parity #30023induction 2020-12-01 STL Request clarification on wing measurement #29640aero
	Road America Runoffs 20202020-10-02	2:31.420Danny Steyn · fastest of 33 · top 5 within 3.1s	2:32.115Joe Moser · fastest of 30 · top 5 within 1.5s	132.9Darin Treakle	2:12.806Scott Rettich · fastest of 25 · top 5 within 0.6s	2:13.271Owen McAllister · fastest of 23 · top 5 within 0.7s	143.4Owen McAllister	-18.844squal -18.614s	87.6%qual 87.7%	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	-10.724squal -10.466s	93.0%qual 93.1%
19 rule changes (STL: 11, FE2: 2, F5: 6)5 induction · 4 engine · 2 weight · 1 aero · 1 cars added · 1 tyres & wheels · 2 wording · 3 othershowhide 2020-10-01 F5 Request to Update Suzuki Engine Years for F500 #29453engine 2020-09-01 FE2 FE/FE2 Oil Cooler #29293wording 2020-08-01 STL Minimum Weight Determination #27695weight 2020-08-01 STL 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 STL Request for Addition to GT3 Approved Turbo List #27576induction 2020-06-01 STL Request to add 2016-2019 GMX-5 Spec line #28604cars added 2020-06-01 STL Request to update PN for MX-5 #28622wording 2020-06-01 STL Correction - Clarification Honda/Acura B18B engine Letter # 26209 #28873engine 2020-05-01 STL STL Honda B18 restrictor changes #28794induction 2020-04-01 STL Change GM LNF 2.0 Allowance to LSJ Engine for Viable STL 2.0 #27884engine 2020-04-01 STL Acura/Honda B18C engine chart. Reduce the current 54 mm flat plat #28663induction 2020-04-01 STL Mazda MZR engine chart. Reduce the current 55 mm flat plate to 53 #28664induction 2020-03-01 STL Request to add wheel part numbers #28342tyres & wheels 2020-01-01 F5 Change 600cc restrictor size #27883induction 2019-12-01 FE2 FE / FE2 Update Rules #27624weight
	Virginia International Raceway Runoffs 20192019-10-05	2:07.203Danny Steyn · fastest of 36 · top 5 within 1.8s	2:07.273Cliff Ira · fastest of 35 · top 5 within 1.4s	134.8Cliff Ira	1:51.062Liam Snyder · fastest of 20 · top 5 within 1.3s	1:52.154Liam Snyder · fastest of 19 · top 5 within 0.7s	142.6Robert Vanman	-15.119squal -16.141s	88.1%qual 87.3%	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	-9.701squal -9.842s	92.4%qual 92.3%
12 rule changes (STL: 11, F5: 1)5 weight · 2 induction · 2 suspension & brakes · 1 cars added · 1 engine · 1 wordingshowhide 2019-10-01 STL Request to Classify Spec MX-5 Challenge in STL #27399cars added 2019-08-31 F5 Request for Weight Increase for Motorcycle Powered Cars #27214weight +25 lbs 2019-07-01 STL Request clarification for manifold and throttle in STU #27004induction 2019-05-31 STL Request Restrictor Plate correction #26779induction 2019-05-01 STL Request Ride Height Clarification #26597suspension & brakes 2019-03-01 STL Request to Allow VW 1.8L Engine #25614engine 2019-03-01 STL Request to reduce weight of RX8 with Renesis rotary #25781weight -100 lbs 2019-03-01 STL Request for Open Brake Pads On Mazda MX-5 Cup NC #25821suspension & brakes 2019-03-01 STL Request to clarify B18C1 GSR Honda B motor table #26209weight 2019-03-01 STL Port Matching #26415wording 2019-01-01 STL Request to equalize FPR Reduction on all B-Series Vtec Engines #24746weight 2019-01-01 STL Request E&O for Mazda Miata Spec Line #25955weight
	Sonoma Raceway Runoffs 20182018-10-10	1:49.138Danny Steyn · fastest of 19 · top 5 within 2.5s	1:49.754Danny Steyn · fastest of 17 · top 5 within 2.5s	103.2Craig McHaffie	1:35.040Flinn Lazier · fastest of 9 · top 5 within 1.5s	1:35.563Flinn Lazier · fastest of 9 · top 5 within 1.7s	126.8Scott Rettich	-14.191squal -14.098s	87.1%qual 87.1%	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	-7.263squal -7.331s	93.4%qual 93.3%
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25	1:52.647Adam Roberts · fastest of 57 · top 5 within 0.8s	1:52.589Eric Kutil · fastest of 50 · top 5 within 1.2s							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		-9.729squal -9.511s	91.4%qual 91.6%
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19	1:35.439John Schmitt · fastest of 34 · top 5 within 1.5s	1:36.625Kevin Boehm · fastest of 31 · top 5 within 0.6s							1:28.528Calvin Stewart · fastest of 14 · top 5 within 3.9s	1:29.853Steven Thompson · fastest of 12 · top 5 within 4.5s		-6.772squal -6.911s	93.0%qual 92.8%
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21	2:09.672Kevin Boehm · fastest of 37 · top 5 within 2.5s	2:10.269Kevin Boehm · fastest of 37 · top 5 within 2.1s							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		-6.971squal -7.848s	94.6%qual 93.9%

By track

Track	Events	Typical % of STL	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 STL'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.