On-road and off-road: tracks, tyres and the rules for each.

The basic split

Wikipedia describes on-road cars as built for flat surfaces and off-road cars for rough terrain. The bodies organise around the same line. IFMAR's World Championship rule books are separate for track (on-road) and off-road classes in both nitro and electric, and EFRA's 2024 AGM report names separate sections for 1/8 Buggy (off-road), IC Track, and the electric 1/10 touring car, 1/12 track and 1/10 off-road classes. The BRCA, in the UK, lists circuit and off-road as separate disciplines on its 2026 membership page.

On-road: circuits on carpet and asphalt

The track

EFRA's electric rules (Handbook 2026, Appendix 3, version 4, A.1.1 to 1.3) set a minimum track length of 120 m, with the farthest point no more than 50 m from the driver's rostrum. The indoor on-road surface is needle carpet. 1/12 cars race indoors on carpet only, and 1/10 saloon (touring) cars on asphalt or carpet. EFRA also asks for track designs that reduce the need for marshals to step in, using smooth obstacles (A.1.1.15).

IFMAR's minimum requirements for affiliated tracks (7 March 2021) are a separate matter: at least 120 m or a 15 x 30 m space indoors, and at least 250 m outdoors. IFMAR states that affiliation alone does not qualify a track to host a World Championship.

The cars

• IFMAR 1/8 IC track (2023, 5.12 to 5.13): bodies are one-eighth scale reproductions of full-size sports or prototype racing cars, worded in the rule as FISA, IMSA or CanAm sport classes.
• IFMAR 1/10 IC track (2024, 5.3 to 5.11): a 200 mm four-wheel-drive nitro touring car with 1:10 touring car (sedan) body reproductions.
• EFRA 1/10 electric touring car (Appendix 3, B.7.1 and 7.2): bodies follow EFRA's guideline, based on real touring cars at least 420 mm long, with no GT or sports car bodies; fixed single-ratio transmission and independent suspension on all four wheels.
• EFRA 1/12 (Appendix 3, B.6): LMP cars representing prototype sports cars, and a GT 17.5 class.

Tyres

IFMAR uses a controlled tyre at 1/8 IC track World Championships (2023, 5.4 and 5.5): for dry racing a controlled rim and foam tyre of one brand is handed out and fitted in a controlled area. EFRA's 1/10 touring car and front-wheel-drive classes use moulded tyres only, with no sponge, and at European Championships only the tyre agreed by the section meeting (Appendix 3, B.7.4.1 and 7.4.2).

Rain

Outdoor on-road racing has its own weather rule at IFMAR: in the 1/8 IC track rules (2023) and the 1/10 IC track rules (2024, 2.10.11), if 75% of the main final has been run before rain starts, the race is declared.

Off-road: rough tracks

The track

EFRA's 1/10 electric off-road track must be at least 3 m wide and no more than 250 m long (Appendix 3, A.1.1 to 1.3). The IFMAR 1/8 IC off-road rules (2024, 3.8) require that track markers be shaped so cars are not thrown into the public, and that barriers protect spectators, competitors, marshals and officials.

The cars

• IFMAR 1/8 IC off-road (2024, 2.1 and 2.2): length at most 550 mm, width at most 310 mm at any point of suspension travel, height at most 250 mm including roll bar; the front bumper must be flexible plastic with no metal and rounded edges, to limit harm to other cars, marshals or any person.
• IFMAR 1/10 electric off-road (2019, 4.1 to 4.4): two classes, 2WD (rear-wheel drive only; front-wheel-drive cars run in 4WD) and 4WD (effective drive to the front wheels); width at most 250.0 mm.
• EFRA 1/10 electric off-road (Appendix 3, D.1.2 and D.2): 2WD and 4WD both run, and drivers may enter both; a 4WD car needs effective front drive.

IFMAR and EFRA give different maximum lengths for 1/10 electric off-road cars: 457.2 mm (18.00 in) in IFMAR's electric off-road rules (2019, 4.2), and 460 mm in EFRA's Handbook 2026 (Appendix 3, D.2). Both give 250 mm width and the same minimum weights. Each figure applies only at that body's events.

Tyres

IFMAR's 1/8 IC off-road tyres must be black, apart from sidewall lettering and a small hardness mark, with a wheel and tyre diameter of 109 to 120 mm; applying any tyre additive inside the event perimeter brings immediate disqualification (2024, 2.4). In 1/10 electric off-road, IFMAR's Electric section chooses controlled tyres and inserts for the controlled parts of the event, commercially available in all four blocs, at most 44.45 mm wide and 90.00 mm in diameter (2019, 4.2.11).

Weather

IFMAR's 1/8 IC off-road rules (2024, 3.1) say racing goes on in rain "within reason" and is suspended for heavy electrical storms, as the Race Director decides with the Referees. EFRA's General Rules (2024, 5.3.11) apply across its events: if a race is interrupted for more than 60 minutes for reasons outside the organiser's control, the referees and Race Director decide with the EFRA representative whether to cancel or continue.

Separate days for 2WD and 4WD

At national level, the BRCA's 2026 South West 10th off-road regionals run 2WD and 4WD on separate days (BRCA series page). That is one regional series' format; the BRCA's 2026 section rules were not read.

Oval

Oval racing is a third format in some countries. The NZRCS Rulebook 2026 (version 1.2) covers 1/10 electric oval racing in New Zealand, with contact classes (Superstocks, Stockcars, Streetstocks) and non-contact classes (Saloon Cars, Modifieds). The BRCA also lists oval as a discipline.

The class limits on each surface are on the classes, and how a meeting runs on either surface is on how a race meeting works.