Wondering what engine to run in your 1/8 nitro buggy or truggy? O.S. takes three of the top four spots, led by the O.S. Speed B21 Adam Drake. We counted the setups saved in the RC Setup App since January 2024: 499 racers named an engine, and O.S. leads with 211 of them, followed by REDS at 70 and Ultimate Racing at 55. Buggies and truggies run the same .21 engines, so they share one list.
The number under each engine is how many racers run it. Counts updated November 2026.
Buy links to AMain may earn us a commission. That doesn't change the order: racers decide that.
Setting up the rest of the car? See the most popular glow plugs, fuel, pipes, servos and shock oil for 1/8 off-road.
Most popular engines for 1/8 nitro buggies and truggies
This list covers engines with at least 10 racers. Most racers name an edition or generation, and those are counted together under one engine.
1. O.S. Speed B21 Adam Drake
78 racers
The most popular engine in 1/8 nitro buggies and truggies, and the top pick in truggies too, with 12 of its 78 racers. Racers name the AD3 most, then the AD2, so editions are counted together. The Mugen MBX8R is its most common car. The button goes to the current AD4, which O.S. built to Adam Drake's spec with a revised 3-port liner and crankshaft.
Buy the AD4 at AMain (opens in new tab)
2. O.S. Speed B21 (B2101 to B2105)
66 racers
O.S.'s numbered B21 series, counted together across generations. Racers name the B2105 most, then the B2104. It's mostly a buggy engine here, with 62 of its 66 racers in a buggy, led by the Mugen MBX8R and Kyosho Inferno MP10. The button goes to the B2105, the fifth generation, with a DLC-coated crankshaft.
Buy the B2105 at AMain (opens in new tab)
3. REDS 721 Scuderia / Superveloce
41 racers
The top engine outside O.S. Racers name the Scuderia and the Superveloce across several generations, so they're counted together. It's spread across cars: the HB D8 World Spec, Mugen MBX8R and Associated RC8B4.1 lead. The button goes to the current Superveloce Gen5, sold as a combo with a REDS 2143 pipe.
Buy the 721 Gen5 combo at AMain (opens in new tab)
4. O.S. Speed B21 Ronda Drake
17 racers
Most of its 17 racers name the Ronda Drake 2, and the Sparko F8 is its most common car. The RD2, shown here, is discontinued, so the button goes to O.S.'s current Drake engine, the Adam Drake AD4.
See the AD4 at AMain (opens in new tab)
5. Ultimate Racing MXR
15 racers
The truggy pick of this list: 7 of its 15 racers run it in a truggy, led by the Tekno NT48 2.2. Racers name the MXR and MXR V2, counted together. The MXR V2 is discontinued, so the button goes to its successor, the MXR V3.
See the MXR V3 at BeachRC
6. ProTek Samurai RM.1
15 racers
Built with Ryan Maifield. Racers name the RM.1 and older Samurai engines, counted together. 5 of its 15 racers run it in a truggy. It's a 3-port .21, and ProTek says the RM.1 gets nearly 60 seconds more per tank than before.
Buy the RM.1 at AMain (opens in new tab)
7. Picco P3TT / P3TX
14 racers
Racers name the P3TT and the newer P3TX about equally, so they're counted together. The Kyosho Inferno MP9 TKI4 and Associated RC8B4.1 lead. The button goes to the P3TX.
See the P3TX at RSRC
8. REDS 521
11 racers
REDS' step down from the 721. Most of its 11 racers name the 521 Sport. The button goes to the current 521 Competizione S-Line, a 5-port .21 for buggies and truggies that REDS pitches on value.
Buy the 521 Competizione at AMain (opens in new tab)How we counted
We count anonymous totals from setups saved in the app for 1/8 nitro buggies and truggies. A racer counts once per engine no matter how many setups they've saved, and a value only counts if the racer entered it themselves, not if it came along with a copied setup. Editions and generations of one engine are counted together, and names that could mean more than one engine, like a bare "O.S.", count toward the brand but not an engine. Specs come from the retailer's listing for the engine each button goes to.
