Gas vs Electric RC Planes: Choosing the Right Power System

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Most pilots ask which plane to buy first. The next question usually arrives quickly: gas or electric? The trouble is that "gas" gets used for two unrelated things, and a lot of advice online lumps them together. This page separates them, and it sticks to what can be checked. Everything below is based on manufacturer specifications, engine and battery manuals, AMA documents and US Department of Energy data, not on our own flying. Where a number comes from a maker, the text says so, and prices are left out because they change weekly.

The short version: electric is the sensible default for most newcomers and for most sport flying. Glow is a hobby in itself, with a ritual that some pilots love. Gasoline earns its place in big airframes and for pilots who fly often. The more useful discovery is that many mid-size and large airframes accept more than one power system, so the choice is often made after the plane is picked.

Three power systems, not two

Electric uses a battery, an electronic speed controller (ESC) and a brushless motor. Nothing burns. The energy is stored in a lithium polymer (LiPo) pack, covered in the LiPo battery guide, and the motor choice is covered in the motors guide.

Glow, often called nitro, burns a fuel that is mostly methanol with lubricating oil and, in many fuels, some nitromethane. A glow plug lit by an external driver starts the engine, and the heat of combustion keeps it going. Per the Evolution Engines manual, the fuel is mostly methanol, which "attracts moisture", and sunlight can break down nitromethane.

Gasoline burns pump-type fuel mixed with two-stroke oil and ignites it with an electronic spark. There is no glow plug and no driver. The gas engines discussed here run from the 15 cc class upward. The gas engine guide covers sizing, and the fuel guide covers what goes in the tank.

Side by side

Electric: what the specs say

An electric airplane is simple to describe. A motor spins the prop, the ESC meters the current and the pack supplies it. The ESC guide and the propeller guide cover the two parts people tend to size last.

The E-flite Apprentice STS 1.5m shows how complete an electric package can be. Horizon Hobby calls it the "Official Trainer of the Academy of Model Aeronautics (AMA) and many clubs worldwide". It has a 59.02 in (1,499 mm) EPO foam airframe, a BL15 840 kV brushless motor, a 30 A ESC and a 3S pack. Horizon recommends a 3S 3200 mAh battery for overall performance, or a 3S 4000 mAh pack for "longer flight times up to 20-30+ minutes". That is a maker claim for the best case, so treat it as an upper bound. When checked in October 2026, the RTF Basic and BNF Basic were on backorder at Horizon and the original RTF was discontinued, so availability is worth confirming before planning around it. The trainer guide lists alternatives, and the beginner picks cover other first planes.

For a pilot past the trainer stage, the E-flite Turbo Timber Evolution 1.5m is a good example of how far electric foam has come. Horizon lists a 61.22 in (1,555 mm) span, an 800 Kv motor, an 11x7.5 three-blade prop, 3S or 4S power, flaps, leading-edge slats and AS3X plus SAFE stabilization, and describes it as a great next step after a trainer. The BNF Basic and PNP versions that include floats were both listed as in stock when checked. A foam plane like this is a good picture of what electric does best: it starts instantly, needs no engine tuning and flies the same on the hundredth flight as on the first.

What electric asks of the pilot

Electric trades engine management for battery management. A few rules appear again and again in the sources:

• Use a charger made for LiPo packs and check the cell count and charge rate before every charge. The AMA Flight School lesson states that each cell charges to 4.20 V and should not be allowed to drop below 3.2 V.
• Horizon's LiPo safety sheet says never to alter, puncture or impact batteries and never to store loose batteries together. It gives a storage temperature range of 40 to 120 F (4 to 49 C) and says not to store packs in a full-sized vehicle.
• For storage, Horizon points to about half capacity, which is roughly 3.8 V per cell. Spektrum Smart G2 packs handle this on their own and discharge to 3.90 V after 72 hours, per Spektrum.
• Take the pack out of the airplane after each flight. The E-flite manual for the Carbon-Z Cessna 150T notes that the ESC's low-voltage cutoff pulses the motor to reserve some battery power for control and landing, and says to disconnect the battery after use.

The LiPo battery guide goes through charging and storage in more detail. The practical point is that electric hazards are concentrated in the battery, so the discipline is concentrated there too.

The flight-time ceiling

Electric flight time is set by pack energy. A Spektrum 3S 2200 mAh Smart G2 pack stores 24.42 Wh and weighs 225 g, per the Horizon listing. Bigger models need bigger packs, or two. That pushes weight up and flight time becomes a trade between capacity and wing loading. Most sport sessions work around this by carrying several packs and swapping between flights.

Glow: what the manuals say

Glow engines are the traditional answer for the .40 to .90 class. The O.S. 46AX II is the engine most guides cite in this class, and Horizon listed it as on backorder when checked. The Evolution .46NX, which Horizon described as replacing the popular .46NT, is discontinued. Stock of glow engines is clearly thinner than it used to be, so check before building a plan around one.

Fuel and care

The manuals are consistent. Saito's large single-cylinder glow manual recommends a fuel containing 20% oil and 10 to 15% nitromethane, advises against fuels made entirely of castor oil, and recommends after-run oil. Its break-in advice is to keep the engine under 4,000 rpm for the first 10 minutes, and it considers forty minutes of break-in enough before the first flight. Evolution's manual covers storage: keep fuel in a metal can, squeeze the air out of containers and replace glow plugs that show a twisted element, aluminum bumps, a dull white-powder element, or that will not stay lit.

Field box

Glow is not just an engine. A typical field setup includes:

• a glow driver such as the Du-Bro Kwik Start Glow Driver, which Horizon listed as in stock, along with the XL version
• a 12 V electric starter (Sullivan's Deluxe starter is discontinued and the Dynatron was on backorder when checked)
• a manual fuel pump such as the Hangar 9 Ultra Fuel Pump for gas and glow, plus a Hangar 9 Pro Fuel Filter, both listed in stock
• a field box with airplane cradles; the Hangar 9 Flight Pack Field Box and its cradles were listed in stock

The Hangar 9 Ultra Fuel Pump works for both gas and glow, which is useful for a pilot who might move up later.

Why people still choose glow

There is a real case for it. A glow engine is a mechanical hobby. The tuning, the sound and the field routine are the point for many pilots, and a balsa airframe such as the SIG Kadet LT-40 can take a glow engine, as SIG's own listing shows. The cost is more to manage: the manuals above cover plug wear, fuel storage, break-in and after-run oil, and each one is a step that electric does not have.

Gasoline: what the manuals say

Gas engines suit larger airframes. The O.S. GT15 is a good reference for the 15 cc class. Horizon lists a displacement of 0.912 cu in (14.95 cc), a mix ratio of 30:1 to 50:1 and a CM6 plug. It was in stock when checked, as was the O.S. GF30 II 30 cc four-stroke. The gas engine guide covers the rest of the range.

Fuel is not one-size-fits-all

Old advice says "87 octane at 30:1", but the manuals disagree with each other. The Saito four-stroke gasoline manual specifies 91 octane unleaded with 100% synthetic two-stroke oil at 20:1 for break-in and continuous operation. It says fuel with up to 10% ethanol "has been tested and found to work fine". The O.S. GT15 calls for 30:1 to 50:1. The right answer is always the one in the manual for the engine in the airplane.

Saito's manual also lists the habits that separate a smooth gas engine from a troublesome one: use a filtered clunk, avoid silicone fuel line, use a tachometer during break-in, expect valve adjustment every 1 to 2 hours on those four-strokes, and do a range check with the engine running and not running. It also says an electric starter is highly recommended.

What gas asks of the pilot

Gas removes the glow driver, but adds an ignition system to keep charged: Saito's manual says to charge the ignition and radio batteries before the first flight of the day. Gas engines are offered in the larger airframes of Horizon's lineup, such as the 30 cc Ultra Stick. The giant-scale guide lists the models where gas power is common, and the ground-handling guide covers the carts and tugs that make these planes manageable.

Airframes that take any power system

Past the small foam models, many airframes are not tied to one power system. That is a useful discovery, because the airplane can be chosen first.

The J-3 Cub pair is the cleanest example. Horizon sells the same 82.5 in (2,096 mm) giant-scale replica as an ARF that accepts a .62 four-stroke glow engine, an 11 cc four-stroke gas engine or an equivalent electric system, and as a plug-and-play electric version with a 4260-480Kv outrunner, a 70 A Smart Lite ESC and four metal-geared servos. The ARF lists about 20 hours of assembly, the PNP about 4. Horizon lists both at about 8.5 lb (3,855 g) without a battery.

The SIG Kadet LT-40 EGV page says the airplane was "redesigned to accommodate either electric or glow power". SIG lists .40 to .46 two-stroke or .40 to .54 four-stroke glow engines, or a 500 to 800 W brushless outrunner with a 50 to 75 A ESC and a 3S or 4S pack of 4000 to 5000 mAh. That is useful because the traditional balsa trainer shape can be flown without any fuel at all. The Hangar 9 Carbon Cub 15cc, once the standard example of this idea, is discontinued at Horizon.

One caution about conversions: an ARF that says "or equivalent electric power system" leaves the motor, ESC and pack up to the builder. The Ultra Stick page, for instance, names a Power 160 motor on a 10S 4400 mAh pack, which is a very different electrical package from a trainer. Check the motor guidance in the motors guide and the ESC sizing rules before ordering parts.

Noise and field access

Noise is the part of this decision that reaches beyond the pilot. The AMA's sound document says it plainly: "By a wide margin, the largest contributor to the loss of flying sites is the noise model aircraft produce."

The AMA numbers are specific:

• Local ordinances "normally" fall between 50 and 65 dB at the property line.
• A sample club standard is 96 dB measured at 20 feet over sod, and 98 dB over a hard surface.
• Readings use the A weighting, with the meter about two feet above the surface and in line with the prop.
• Sound pressure drops 6 dB each time the distance doubles. From 96 dB at 20 ft the AMA table gives 90 dB at 40 ft, 84 dB at 80 ft, 78 dB at 160 ft, 72 dB at 320 ft, 66 dB at 640 ft and 60 dB at 1,280 ft.
• In one engineering study cited by the AMA, a model at the 96 dB baseline measured at 3 meters (9.8 feet) had to stay at least 349 feet from a property line to meet a 65 dB ordinance.

Those numbers explain why noise rules differ so much between fields. The same airplane can be fine at a rural site and a problem at a suburban one. Club rules vary, and the AMA document treats its figures as samples, so ask the club that runs the field. The beginner flying guide is the place to start for pilots who have not yet found a field.

The AMA also gives a quick fix list that applies to gas and glow:

1. Add blades rather than diameter. Most of the noise comes from the propeller, not the engine, because the tips go supersonic. A larger two-blade prop slows the engine but speeds up the tips. A three-blade prop lets the diameter and rpm come down. As a rule of thumb the AMA suggests reducing diameter or pitch by an inch, or both.
2. Fit as large a canister muffler as possible. After-market mufflers generally do better than stock ones.
3. Soft-mount the engine so the airframe does not act as a drum.

Electric planes still make prop noise, but they skip the engine and exhaust. For a pilot whose only available field has a strict limit, that can decide the question.

Energy: what a gallon holds

Gas and electric are sometimes compared by how much "fuel" each takes. The Department of Energy publishes the numbers needed for an honest version of that comparison. Gasoline holds between 112,114 and 116,090 Btu per gallon (lower heating value), and electricity is 3,414 Btu per kWh. Dividing, one gallon holds roughly 33 to 34 kWh of energy. A 3S 2200 mAh Smart pack holds 24.42 Wh. A gallon therefore holds well over a thousand times the energy of that pack.

That tells you about energy content only. Engines and motors turn that energy into thrust with very different efficiencies, so this page does not claim one. What the comparison does show is the scale of the gap: matching a tank of fuel with batteries means carrying a great many packs.

Which to choose

New pilots. Pick electric. There is no engine to tune, the learning curve is all about flying, and trainers like the Apprentice STS pair an ESC and stabilization to forgiving foam. The beginner flying guide covers the next steps. Glow can come later, and the skills carry over.

Sport pilots who like machinery. Glow or gas both make sense. If the goal is the mechanical routine, an ARF built for glow power will deliver it. If the goal is a bigger airplane with less fuss over sourcing, a gas engine such as the GT15 class is worth a look. A club mentor makes either path easier.

Large-scale and scale-airframe pilots. Gasoline engines are offered across Horizon's larger airframes, and electric is possible in the mid-range, as the J-3 Cub PNP shows. The giant-scale guide is the place to start.

Jets, FPV and precision flying. Electric is the practical choice for EDF models. See the EDF jet guide and the jet picks for specific models.

Pilots with a noise-limited field. Electric, or a gas or glow engine with a three-blade prop, a big canister muffler and a soft mount, then a check against the club limit.

Safety on both sides

Neither system is risk-free. Electric concentrates the hazard in the battery during charging, storage and transport, which is why the Horizon and AMA documents focus on charger settings, storage conditions and handling. Combustion concentrates the hazard at the prop during starting and tuning. Keep bystanders out of the prop arc, wear eye protection, and for gas, follow the manual's break-in and range-check steps. For electric, charge on a non-flammable surface or in a LiPo-safe charging bag, and never leave charging packs unattended.

Frequently asked questions