BoP Lab / Classes / F5

F5 vs FE vs SRF vs STL pace at every track

Lap times across years say as much about the weather as the class. % of F5 is each class's best lap as a share of F5'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.

Class · click a class to switch, + to compare alongside (up to 4: remove one to add another)

ASB-SpecEPF5×FAFCvsFE ×FE2FFFPFVFXGT1GT2GTXHPPP2SMSMXvsSRF ×SRF3vsSTL ×STUT1T2T3T4Show 48 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: F5 100.0% of F5 Matthew Strand, Daytona International Speedway Runoffs 2015 race · FE 95.8% of F5 Mark Snyder, Sonoma Raceway Runoffs 2018 qualifying · SRF 108.2% of F5 Thomas Kirchman, Indianapolis Motor Speedway Runoffs 2017 qualifying · STL 90.1% of F5 Danny Steyn, Virginia International Raceway Runoffs 2022 race

% of F5Lap times

F5FESRFSTLsolid race · dashed qualifying · slower is lower

F5FESRFSTLsolid race · dashed qualifying · each class's best lap as a share of F5's at the same event (the reference class, changeable above); 100% is level, less is quicker, so up the chart is quicker

	Event	F5			FE					SRF					STL
	Event	Qual best	Race best	Trap	Qual best	Race best	Trap	vs F5	% of F5	Qual best	Race best	Trap	vs F5	% of F5	Qual best	Race best	Trap	vs F5	% of F5
	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%)
9 rule changes (FE: 2, SRF: 3, STL: 4)3 weight · 1 engine · 1 removed · 1 suspension & brakes · 3 othershowhide 2026-09-01 SRF GCR Rain/Brake Light Correction #40579suspension & brakes 2026-07-01 STL Spec Line Clean Up #40344removed 2026-06-01 STL Calculating Weight #40224weight 2026-04-01 STL Classifications #39885weight 2026-03-01 SRF SRF3 Spark Plugs #39899other 2026-01-01 FE FE & FE2 Rule Updates #39484engine 2026-01-01 STL Weight adjustment for STL #39579weight 2025-10-01 FE FE & FE2 Bubble Tail #38978other 2025-10-01 SRF Add HD Oil Cooler #38979other
	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%)
7 rule changes (FE: 2, SRF: 2, STL: 3)3 weight · 1 suspension & brakes · 1 tyres & wheels · 2 othershowhide 2025-09-01 FE FE & FE2 Rule Updates #38901weight 2025-08-01 STL Lotus Weight Reduction #38772weight -50 lbs 2025-05-01 STL E&O: SMX Allowance in STL #37945weight 2025-04-01 SRF Driver Safety & Comfort #37966other 2025-04-01 SRF Update SADEV transmission specs #37992other 2024-12-01 FE Brake Line to A-Arm Covers #37110suspension & brakes 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%)
19 rule changes (FE: 5, SRF: 10, STL: 4)5 tyres & wheels · 3 suspension & brakes · 2 induction · 2 weight · 2 wording · 5 othershowhide 2024-10-01 SRF Update SRF3 Air Filter Rule #36681other 2024-10-01 SRF Update SRF Brake Rotor Thickness #36687suspension & brakes 2024-10-01 SRF Hoosier Tire Decal Placement #36739tyres & wheels 2024-09-01 FE Protest Fee Clarification #36540wording 2024-09-01 FE Update on Letter 36620 with new Hoosier Contingency Decal Info #36625tyres & wheels 2024-09-01 SRF Protest Fee Clarification #36540wording 2024-09-01 SRF Update to Letter 36619 with new Hoosier Contingency Decal Info #36624tyres & wheels 2024-08-01 FE Hoosier Tire Decal Placement #36435tyres & wheels 2024-08-01 SRF Update Rain Tire Rule and Hoosier Decal Placement #36436tyres & wheels 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 FE Update FE Rain Light Rule #34707other 2024-01-01 FE FE/FE2 rule update #35269other 2024-01-01 SRF Update SRF Rain / Brake Rule #34706suspension & brakes 2024-01-01 SRF Update SRF Brake Light Rule v1 #34853suspension & brakes 2024-01-01 SRF SRF / SRF3 Rule Updates #35268weight 2024-01-01 STL Alternate Carburetor Request for 79-85 RX7 12a #35181induction 2023-10-01 SRF SRF Radiator Rule Update #34805other
	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%)
8 rule changes (FE: 3, SRF: 3, STL: 2)4 tyres & wheels · 2 suspension & brakes · 1 aero · 1 othershowhide 2023-06-01 SRF Hoosier SRF Wet Front Tire Rule Update #34189tyres & wheels 2023-06-01 STL Clarify STL table B - IT spec notes on Tires #34187tyres & wheels 2023-05-01 SRF Update SRF Front W2 Rain Tire Part Number #34118tyres & wheels 2023-04-01 FE Update FE SADEV Transmission Rule #33883other 2023-03-01 SRF Update SRF Brake Rule #33469suspension & brakes 2023-01-01 STL Spec MX5 in STL #33473tyres & wheels 2022-10-01 FE Brake bias adjuster clarification #33084suspension & brakes 2022-10-01 FE FE Front and Rear Wing Update & Clarification #33089aero
	Virginia International Raceway Runoffs 20222022-09-24	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%)											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%)	-14.030squal +7.785s	90.1%qual 106.6%
18 rule changes (F5: 6, FE: 4, SRF: 3, STL: 5)4 engine · 4 induction · 3 tyres & wheels · 2 weight · 1 suspension & brakes · 1 wording · 3 othershowhide 2022-09-01 F5 Intake Boots Correction #33028induction 2022-09-01 FE Engine Heat Shield & Insulation #33019engine 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 2022-06-01 FE Update FE/FE2 Tire Rule #32613tyres & wheels 2022-06-01 FE Master cylinder clarification #32669engine 2022-06-01 SRF SRF Tire Rule Update #32614tyres & wheels 2022-06-01 SRF Brake, seal, and air filter clarifications #32670suspension & brakes 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 2021-12-01 FE Two FE2 Rule Updates #31524other 2021-12-01 SRF Three Updates to SRF Rules #31523weight
	Indianapolis Motor Speedway Runoffs 20212021-09-25	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											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	+19.571squal +9.046s	119.0%qual 108.8%
28 rule changes (F5: 3, FE: 4, SRF: 6, STL: 15)5 engine · 4 suspension & brakes · 4 tyres & wheels · 3 weight · 2 aero · 2 induction · 1 cars added · 3 wording · 4 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 2021-08-01 SRF SRF Wet Tires #30849tyres & wheels 2021-08-01 SRF SADEV-SRF3 Transmission #30926other 2021-08-01 SRF SRF Update Maintenance, Repairs and Seals #30961engine 2021-07-01 FE FE Tire Rule Changes #30754tyres & wheels 2021-07-01 FE Radiator Screens Clarification #30792wording 2021-06-01 F5 Request to Allow Rotax 593 HO Engine #30712engine 2021-06-01 FE FE Radiator Screens #30575other 2021-06-01 SRF SRF3 Alternator Pulley #30684weight 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 SRF Mandatory identification: #30223engine 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 FE FE / FE2 Spring Updates #29689suspension & brakes 2020-12-01 SRF SRF Shocks, Springs and Ride Height. #29688suspension & brakes 2020-12-01 STL Request clarification on wing measurement #29640aero
	Road America Runoffs 20202020-10-02	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											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	+10.724squal +10.466s	107.6%qual 107.4%
27 rule changes (F5: 6, FE: 5, SRF: 5, STL: 11)5 induction · 4 engine · 4 weight · 3 aero · 3 suspension & brakes · 2 tyres & wheels · 1 cars added · 1 wording · 4 othershowhide 2020-10-01 F5 Request to Update Suzuki Engine Years for F500 #29453engine 2020-10-01 FE FE Gurney Flap Spec Update #29445aero 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 FE FE Gurney flap wicker clarification #28885aero 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 FE FE spring rule update changed to November 1, 2020 #28814suspension & brakes 2020-05-01 SRF SRF Bump Stop Correction #27019suspension & brakes 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 2020-01-01 FE Request for FE / FE2 preparation rules update #27722weight 202-01-01 SRF SRF Rain / Brake Rule - BoD approved as follows #34958suspension & brakes 2019-12-01 FE FE / FE2 Update Rules #27624weight 2019-12-01 SRF SRF Tire Warmer Rule #27622tyres & wheels 2019-12-01 SRF SRF / SRF3 Nose Weight Reduction #27706weight 2019-12-01 SRF SRF / SRF3 Majors & Regional Class Updates #27723other
	Virginia International Raceway Runoffs 20192019-10-05	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	1:54.710Mark Snyder · fastest of 9 · top 5 within 1.3s	1:55.648Mark Snyder · fastest of 9 · top 5 within 0.9s	135.5James Libecco	-1.924squal -2.651s	98.4%qual 97.7%						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	+9.701squal +9.842s	108.3%qual 108.4%
18 rule changes (F5: 1, FE: 5, SRF: 1, STL: 11)5 weight · 3 suspension & brakes · 3 tyres & wheels · 2 induction · 1 cars added · 1 engine · 1 wording · 2 othershowhide 2019-10-01 FE FE Wet Tire E&O #27365tyres & wheels 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 FE FE Tire Update #27029tyres & wheels 2019-07-01 SRF SRF Dash Windscreen Kit #27028other 2019-07-01 STL Request clarification for manifold and throttle in STU #27004induction 2019-05-31 FE FE Anti-Roll Bar Clarification #26912suspension & brakes 2019-05-31 FE FE / FE2 Updated Bubble Tail Rule #26913other 2019-05-31 STL Request Restrictor Plate correction #26779induction 2019-05-01 STL Request Ride Height Clarification #26597suspension & brakes 2019-03-01 FE Request to Update Hoosier Rain Tire Part Number for the FE cars #26235tyres & wheels 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	1:41.807Jeff Jorgenson · fastest of 5 · top 5 within 6.6s	1:42.491David Lapham · fastest of 5 · top 5 within 9.5s	113.3David Lapham	1:37.517Mark Snyder · fastest of 10 · top 5 within 1.4s	1:38.504Lee Rackley · fastest of 10 · top 5 within 0.8s	124.7Quinten Nelson	-3.987squal -4.290s	96.1%qual 95.8%						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	+7.263squal +7.331s	107.1%qual 107.2%
No rule changes on record between these events
	Indianapolis Motor Speedway Runoffs 20172017-09-25	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		1:39.177Elliot Finlayson · fastest of 35 · top 5 within 1.3s	1:39.726Elliot Finlayson · fastest of 35 · top 5 within 0.8s		-3.134squal -3.959s	97.0%qual 96.2%	1:51.573Thomas Kirchman · fastest of 50 · top 5 within 2.8s	1:53.769Todd Harris · fastest of 45 · top 5 within 0.2s		+10.909squal +8.437s	110.6%qual 108.2%	1:52.647Adam Roberts · fastest of 57 · top 5 within 0.8s	1:52.589Eric Kutil · fastest of 50 · top 5 within 1.2s		+9.729squal +9.511s	109.5%qual 109.2%
No rule changes on record between these events
	Mid-Ohio Sports Car Course Runoffs 20162016-09-19	1:28.528Calvin Stewart · fastest of 14 · top 5 within 3.9s	1:29.853Steven Thompson · fastest of 12 · top 5 within 4.5s		1:27.636Scott Rettich · fastest of 9 · top 5 within 1.7s	1:30.563Hanna Zellers · fastest of 9 · top 5 within 2.2s		+0.710squal -0.892s	100.8%qual 99.0%	1:37.344Mike Miserendino · fastest of 27 · top 5 within 0.8s	1:37.621Todd Harris · fastest of 27 · top 5 within 0.6s		+7.768squal +8.816s	108.6%qual 110.0%	1:35.439John Schmitt · fastest of 34 · top 5 within 1.5s	1:36.625Kevin Boehm · fastest of 31 · top 5 within 0.6s		+6.772squal +6.911s	107.5%qual 107.8%
No rule changes on record between these events
	Daytona International Speedway Runoffs 20152015-09-21	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		1:57.824Scott Rettich · fastest of 16 · top 5 within 1.0s	1:59.040Scott Rettich · fastest of 16 · top 5 within 1.3s		-4.258squal -4.000s	96.5%qual 96.7%	2:14.306Cliff White · fastest of 39 · top 5 within 1.2s	2:16.700Cliff White · fastest of 38 · top 5 within 0.5s		+13.402squal +12.482s	110.9%qual 110.2%	2:09.672Kevin Boehm · fastest of 37 · top 5 within 2.5s	2:10.269Kevin Boehm · fastest of 37 · top 5 within 2.1s		+6.971squal +7.848s	105.7%qual 106.4%

By track

Track	Events	Typical % of F5	Best	Latest
Road America	4	100.0%1 of 4 with F5	100.0%Runoffs 2020	100.0%Runoffs 2020
Virginia International Raceway	3	100.0%2 of 3 with F5	100.0%Runoffs 2019	100.0%Runoffs 2022
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 F5'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.