P-38 vs P-51: Which Was the Better WWII Fighter, and Why Each Ruled a Different Theater

How we compare the P-38 and the P-51

Both fighters changed a lot between 1941 and 1945, so we compare the versions that fought side by side in 1944 and 1945: the P-38J and P-38L against the P-51B, P-51C and P-51D.

We judge them on four measures: speed and climb, firepower, how they fared in Europe, and how they fared in the Pacific. Full specifications for the Lockheed P-38 Lightning and the North American P-51 Mustang sit in our aircraft database.

Why each fighter was built

The Army Air Corps asked for a twin-engine, high-altitude interceptor in a February 1937 specification written by First Lieutenants Benjamin Kelsey and Gordon Saville. Lockheed won the competition on June 23, 1937, and the XP-38 first flew on January 27, 1939, with Kelsey at the controls.

The P-51 began as a British order. In 1940 the British Purchasing Commission asked North American Aviation to build Curtiss P-40 fighters under license, and the company offered a new design instead. The prototype flew on October 26, 1940, 149 days into the contract, with test pilot Vance Breese at the controls.

You can see what the Mustang replaced in our P-40 Warhawk vs P-51 Mustang comparison.

The first Mustangs used an Allison engine with a single-stage supercharger, and their power dropped off above 15,000 feet (4,600 m). A Rolls-Royce Merlin engine with a two-stage supercharger fixed that without costing range. It arrived in the P-51B in 1943, and it is what turned the Mustang into a bomber escort.

Where the P-38 wins

Two engines over open water

The P-38 was used most extensively and successfully in the Pacific. There it combined exceptional range with the reliability of two engines for long missions over water.

After losing one engine, many P-38 pilots still made it home. The P-51 reached the Pacific later, largely because Europe needed it first.

All the guns in the nose

Most American fighters carried guns in the wings, aimed to cross at one set distance. The P-38 grouped its cannon and machine guns in the nose, so the stream of bullets stayed tight at any range.

A Lightning could reliably hit targets at any range up to 1,000 yards (900 m). That concentrated fire was even deadlier against the lightly armored Japanese fighters than against German aircraft.

Climb and ceiling

The database comparison above shows the Lightning climbing at 4,750 ft/min (24 m/s) against the Mustang’s 3,200 ft/min (16 m/s). It also has the higher service ceiling, 44,000 feet (13,400 m) against 41,900 feet (12,800 m).

German pilots noticed. Johann Pichler, a high-scoring ace, said the P-38 in 1943 was much faster in a climb than the Bf 109.

The aircraft of America’s top aces

Richard Bong, the highest-scoring American ace of World War II, scored all 40 of his victories in P-38s. Thomas McGuire, the second-ranking American ace, scored 38.

On April 18, 1943, 16 P-38Gs flew 435 miles (700 km) from Guadalcanal, 10 to 50 feet (3 to 20 m) above the ocean, to intercept Admiral Isoroku Yamamoto, the architect of Japan’s naval strategy in the Pacific. The Americans lost one P-38, and Japanese search parties found Yamamoto’s body at the jungle crash site the next day.

Where the P-51 wins

Faster, above all in a dive

The database comparison puts the Mustang at 441 mph (709 km/h) against the Lightning’s 414 mph (667 km/h). The smaller, more streamlined P-51 was also significantly faster in a dive.

That dive speed is what led to the P-51 replacing the P-38 in most European fighter groups by mid-1944. For how both rank across the war, see our list of the fastest planes of WWII.

The escort that reached Berlin

From late 1943 the P-51B and P-51C escorted Eighth Air Force bombers over Germany, joined by the P-51D from mid-1944. At first the shorter-range P-38s and P-47s covered the start of a raid and handed over to the Mustangs when they had to turn for home.

Captain Eric Brown, who tested the Mustang at Farnborough in March 1944, called it the best escort because of its incredible range, and the best American dogfighter. Reichsmarschall Hermann Göring was quoted as saying, “When I saw Mustangs over Berlin, I knew the jig was up.”

By the end of 1944, 14 of the Eighth Air Force’s 15 fighter groups flew Mustangs.

The bigger score in Europe

By May 8, 1945, P-51 groups of the Eighth, Ninth and Fifteenth Air Forces had claimed some 4,950 aircraft shot down. That is about half of all USAAF claims in Europe, and the most claimed by any Allied fighter in air-to-air combat.

Those are claims, not confirmed kills, and the Mustang paid for them. Losses were about 2,520 aircraft, and ground-attack missions cost more than air combat because the liquid-cooled Merlin was vulnerable to radiator and coolant line damage.

Part of the Luftwaffe’s answer was a jet, the Me 262. We compare it with the Mustang in our P-51 vs Me 262 comparison.

Why the P-38 struggled in Europe

The P-38 did not fail everywhere. Its engine troubles at high altitude appeared only with the Eighth Air Force in England, while other commands were clamoring for as many Lightnings as they could get.

Three problems stacked up. The cooling systems of the G and H models could not handle the uprated engines at high power, and the turbosuperchargers had their own reliability issues.

The cockpit was also too cold. Pilots were often chilled in Northern Europe and at high altitude, because the engines sat too far from the cockpit for easy heat transfer.

The third problem was compressibility. In a high-speed dive the tail shook, the nose tucked under and the controls could lock up, and until the P-38J-25 added dive recovery flaps German pilots knew the Lightnings would be reluctant to follow them down. A Luftwaffe pilot who did not want to fight could simply start a Split S and dive away.

The later Lightnings did better. The improved J and L models flew with great success out of Italy into Germany at all altitudes, and on March 3, 1944, P-38H pilots of the 55th Fighter Group became the first Allied fighters to reach Berlin, on an escort mission whose bombers had turned back.

German pilots had mixed views of the Lightning. Johannes Steinhoff said its tight turning radius made a dogfight daunting, while Kurt Bühligen recalled it as easy to burn.

After 1945

After the war the USAAF chose the P-51 as its standard piston-engined fighter and withdrew the P-38 or gave it a much smaller role. When the Korean War began, the Mustang, by then redesignated the F-51, was the main American fighter until jets such as the F-86 Sabre took over.

A Mustang also flew in the last combat of its kind. In the 1969 Football War between El Salvador and Honduras, a Salvadoran P-51D was shot down by a Corsair in the last aerial combat between piston-engined fighters.

So which one was better?

Over Europe, the P-51 was the better fighter. It was faster, it dived better, it escorted bombers all the way to Berlin, and by the end of 1944 14 of the Eighth Air Force’s 15 fighter groups flew it.

Over the Pacific, the P-38 was the better fighter. Its two engines and long reach suited missions over open water, and it was the aircraft of America’s two top aces.

The two were meant for different jobs. For how they stack up against the rest, see our ranking of the best WWII fighter planes and our guide to American fighter planes of WWII.