Comparing Late-War Spitfire and Mustang Fighters

Two of the Best Fighters of World War II

P-51D Mustang and Supermarine Spitfire FR Mk.XIVe.

We're going to wade into a topic full of minefields here by comparing two of the best fighters of World War II. We are comparing the Royal Air Force's Supermarine Spitfire and the United States Army Air Force's North American Aviation P-51D. Opinions will differ on which warplane was more effective. However, below we will reach a conclusion and defend it.

There are inevitable definitional problems to questions such as “which warplane was better.” The main obstacle in a question like this is that there almost always were many different versions of the same plane flying at the same time. They did not have the same performance characteristics because some represented upgrades, others were modified for different roles, and some were variants of the model. What armament a particular plane carried affected its speed and performance, but heavier armament could make a plane more effective despite the performance drag. Simply comparing numbers is dangerous in this area when all planes under consideration were fast enough and well-enough armed to do their jobs.

There were many variants of these planes, particularly the Spitfire. Here, a Seafire, which was a Spitfire converted for use with the Royal Navy, has a rough landing, losing a propeller as it hits the crash barrier.

Inevitably with these types of comparisons, somebody will chime in that “well, there were five of this earlier experimental model that was faster” or something along those lines (I’ve had that happen to me before). There could be lots of little tweaks to add specific performance characteristics. For example, the number of propeller blades increased from two blades to five at the end as engine plants became more powerful, and the blades became thicker, too. There were many ways to "soup up" a specific plane and give it special performance characteristics. So, those sorts of "you missed this one" comments may be true, but I’m going to focus here on standard fighters flown in standard configurations. That excludes the exceptions, low-production models, and experimental situations.

Just to give some examples of what I mean, the MK XVIII (Type 394) Spitfire was a further refinement of the Mk. XIV but never became operational. The P-51 is treated the same way. Post-war Mustang models such as the F-51H were not even used in Korea. I ignore situations like that.

So, here's how we are going to address this. If you were a Luftwaffe pilot and saw a typical plane below you in December 1944, what could you expect? That's what we are looking at here.

Let's look at the Spitfires first.

A Spitfire Mk. XIV.

The Supermarine Spitfire Mk XIV

Supermarine Spitfires were continually upgraded and had different characteristics by the end of World War II. So, this is difficult to talk about Spitfires because it depends on which Spitfire you are referring to as you get deeper into World War II.

For instance, there was the Mk XVI (type 361). A total of 1,054 Mk XVI Spitfires were built at Castle Bromwich and delivered for service beginning in October 1944. They saw action with the RAF’s 2nd Tactical Air Force in a ground-attack role. The Mk XVI had a Merlin 266 engine, which was the Merlin 66 built under license in the USA by the Packard Motor Company.

A late-war Spitfire. Note the five propeller blades.

The Spitfire XIV (Type 379), however, is what we are going to use for comparison. It used Rolls-Royce Griffon engines (1,528 kW) and entered service on 1 January 1944 with RAF No. 610 Squadron. It equipped 20 squadrons of the 2nd T.A.F. and thus was probably what most people would think of as a “late-war Spitfire.” An Mk. XIV pilot of No. 410 Squadron shot down the first Luftwaffe ME 262 jet fighter on 5 October 1944 and also was the most successful defender against flying bombs. A total of 1055 were built. This version had 2 × 20 mm Hispano Mk II cannon with 120 rounds-per-gun (rpg) in the wing’s outer bays and 2 × .50 cal Browning M2 machine guns, with 250 rpg in the inner bays.

Spitfire Mk. XIV.

Now that we have that clarified, let’s get down to the speed of a “late-war Spitfire.” Its range was about 460 miles (740 km), or about a little more than an hour of flight time, on internal 109.5-gallon fuel tanks. This was poorer range than previous models because the Griffon engine consumed far more fuel per hour than the original Merlin engine. By late 1944, Spitfire XIVs could be fitted with an extra 33 gal in a rear fuselage fuel tank, extending the fighter's range to about 850 miles (1,370 km) on internal fuel plus a 90 gal drop tank. Mk XIVs with "tear-drop" canopies had 64 gallons in rear fuselage tanks. As a result, F and FR Mk XIVEs had a range that was increased to over 610 miles (980 km) on internal fuel alone or 960 miles (1,540 km) with a 90 gal drop tank. Note that even with the drop tanks, the Mk XIV could not reach 1000 miles in range.

The Mk XIV could climb to 20,000 ft (6,100 m) in just over five minutes. It had a top speed (at 25,400 ft (7,700 m)) of 446 mph (718 km/h). The appearance of the Mk XIV was distinctive because it used a five bladed Rotol propeller of 10 ft 5 in (3.18 m) in diameter. The plane was considered difficult to handle but could climb like a beast.

P-51D Mustang 44-15101 of the 356th Fighter Group, 361 Fighter Squadron in flight during World War II.

The P-51D

Now, let’s turn to the North American P-51. There were 6,502 of these built at Inglewood and 1,600 at Dallas - a combined total of 8,102. These planes remained in service long after World War II, so pinning down exactly what they were capable of doing during the war and not just afterward is important. Fortunately, the primary model is easy to pinpoint: the P-51D (the P-51K was similar for all intents and purposes but was made just in Dallas; it differed only by having an inferior propeller).

North American Aviation's P-51D was the mainstay of the USAAF presence in the European Theater of Operations (ETO). This model entered service in mid-1944 (in March and later), but earlier versions also remained in service to the end of the war (P-51Ds never exceeded more than half of the total Mustangs being flown in the ETO). Thus, you might see vastly different performances by two Mustangs flying side-by-side depending on what models they were. The P-51D was powered by the Packard (Rolls Royce Merlin) V-1650-7 (1,695 hp), a license-built version of the two-speed two-stage-supercharged Merlin 66.

A World War II photo of a P-51 clearly showing the 85-gallon (322 liters) drop tank which vastly expanded their effectiveness.

The P-51D had a maximum speed of 440 mph (708 km/h, 383 knots). It had 6 × 0.50 caliber (12.7mm) AN/M2 Browning machine guns with 1,840 total rounds (380 rounds for each on the inboard pair and 270 rounds for each of the outer two pair). Its range standard range was 1000 miles with internal fuel but was 1,650 mi (2,656 km, 1,434 nautical miles) with external tanks. About 8200 of them were built, with 6,600 built at Inglewood and 1,600 built at Dallas. Wing racks enabled the P-51D to carry 500 lb (230 kg) bombs, making it potentially a fighter-bomber. The Hamilton Standard propeller four blades, unlike the Spitfire Mk XIV's five blades.

A Royal Canadian Air Force Spitfire Mk. XIV showing signs of wear.

Comparison

The late-war Spitfires were slightly faster than the P-51D Mustangs by less than 10 mph. This was achieved by using engines that consumed fuel faster and thus gave the Spitfire a dramatically lower range than the Mustang.

The top Luftwaffe pilots who observed both planes passed their judgment as to which was a more difficult competitor. Fighter ace Heinz Bär, who flew over 1000 combat missions, was credited with 208 planes shot down (he claimed 228). This included16 planes shot down while flying in the ME 262 jet fighter. His 124 victories against the Western Allies were second only to Hans-Joachim Marseille's total of 158.

Bär favored the P-51D. He said that the P-51 "was perhaps the most difficult of all Allied aircraft to meet in combat. It was fast, maneuverable, hard to see, and difficult to identify because it resembled the Me 109."

Some captured P-51D Mustangs flew with the Luftwaffe during World War II, but only for testing purposes. I believe this photo is from a post-war film in which surplus P-51s were made up to look like Bf-109s because there weren't any of the latter planes available.

Günther Rall earned credit for the destruction of 275 enemy aircraft in 621 combat missions. Since all but three of his victories were on the Eastern Front, you might think that Rall was not qualified to compare the Spitfire and the Mustang. However, he was transferred back from the Eastern Front to the Defense of the Reich force in March 1944. This was just when the P-51D began appearing over German skies. Rall also was the commander of the German Fighter Leader School for about four months, where he flew all of the Luftwaffe's captured Allied planes. The Luftwaffe’s Zirkus Rosarius was a special unit tasked with evaluating enemy aircraft. It would capture and rebuild them for testing. Rall claimed to have flown 300 hours in the Mustangs.

Spitfire Mk XIV XC-S of No. 26 Squadron RAF in flight.

Rall, who passed away on 4 October 2009, was interviewed by Colin Heaton about his World War II experiences (he also flew for the post-war German air force). The interview originally appeared in the September 1996 issue of World War II magazine. Comparing the many different World War II fighters of both sides that he flew during the war, Rall commented:

The cockpits of all of these enemy aircraft were much more comfortable. You could not fly the Bf-109 for seven hours; the cockpit was too tight, too narrow. The P-51 (cockpit) was for me a great room, just fantastic. The P-38 with two engines was great, but I think the best airplane was the P-51. Certainly, the Spitfire was excellent, but it didn’t have the endurance of the P-51. I think this was the decisive factor. They flew for seven hours, and we flew for one hour and 20 minutes.

The Bf-109 and the Spitfire had roughly the same amount of endurance. The P-51s were considered particularly durable aircraft both in terms of flight time and airframe strength.

All models of the P-51 Mustang were considered very durable, and not just in terms of flight time. There were many tales of pilots flying damaged Mustangs back to base when other aircraft likely would not have made it. 

Rall further reiterated that the P-51D was the best of all the Allied fighters:

Now the big thing in the Home Defense as far as problems was the P-51. The P-51 was a damned good airplane and it had tremendous endurance, which for us was a new dimension. The P-47, which as you know shot me down, we knew right away. It had tremendous diving speed and could run up to 1,400 kilometers per hour, where the Bf-109 was limited to 1,000 kph. I learned this quickly when they chased me, and I could do nothing else. The structural layout design of the P-47 was much stronger, yet I consider the P-51 the best battle horse you had of all the fighter escorts.

Other Luftwaffe pilots had similar sentiments. Reichsmarschall Hermann Goering admitted after the war, "When I saw Mustangs over Berlin, I knew the jig was up."

The late-war Spitfires were faster than the Mustangs, but were they "better"?

Conclusion

So, to summarize, the late-war Spitfires were slightly faster than the P-51D. This made them better for certain missions such as catching and destroying flying bombs. However, the P-51D had a vastly greater range without sacrificing much performance and this made it a more effective combatant. The more time you were able to spend in the air, the more value you had and the more missions you could perform.

One way to think about this is that being in the air longer enabled you to fly deeper missions into enemy territory and enabled pilots to stick with successful operations longer. More range opened up more tactical options and also made the P-51D strategically more useful by protecting bombers. These were options that neither the RAF (aside from the Mustangs it flew) nor the Luftwaffe had.

Thus, the P-51D earned the edge as the superior warplane among those who were in a good position to compare the two.

A North American Aviation P-51D Mustang.

2020