The original M-48A1 had very small range (110 km) and that was the reason for the development of M-48A2 version (by US) with a new gasoline engine and a 90mm gun. The M48-A2C featured a gasoline engine which was very prone to fire. This model  was replaced in 1968 (in US) by the M48-A3 powered by a diesel unit. In the 1970's development of the AVDS 1790 2C/2D series of engines, rated at 750 Horsepower, were utilized in the M60A3, Retrofited AMX-30 Tank, Modernized Centurion Tank, M88A1, Retrofited M47, and Modernized M48A5 Tank.

After the Yom Kippur War in 1973 the United States transfered a large number of M-60s to Israel for replacing the large combat losses. This devepopment created a shortage in US Army tank units and soon it was decided that a number of M-48s would be remanufactured in order to reach the M-60A1 level capabilities. The new version was the M-48A5 equipped with a new M68 105mm gun, new track system and a 12.7mm with a 7.62mm M-60 machine guns. Almost 2,000 M-48A1/2/3s were converted to the A5 version and despite the fact that the armor protection had no match with the M-60s, the A5 had the same armament and engine. 

The M48 vehicle is separated into three compartments: the driver's compartment, the fighting compartment where the Gunner, Loader, and Tank Commander [TC] fought, and the engine compartment. Above the main gun was a 1 million candle-power Xenon searchlight. This light had both a white light and an infrared mode. It was boresighted with the main gun and gunsights so that it could be used to illuminate a target at night. 

The M48 was designed for combat in Europe against Soviet tanks.  When first deployed, the M48-A3 had for the 1960s a state-of-the-art fire control system. At the time computers were mechanical, and range to the target was provided by a stereoscopic range finder, which functioned similarly to a 35mm camera. An end-box on each side of the turret exterior held a prism-type mirror. Turning a hand-crank on the range finder would pivot these mirrors until the double-image in the range finder merged. As the distance between the mirrors is exactly  known, a little trigonometry provided the range (in meters) to the target. This information was displayed on a range indicator, and also fed to the ballistic computer by a rotating shaft. The ballistic computer was a collection of gears and cams--nothing was solid-state--which had a handle so that the gunner could select the type of ammunition that was to be fired. Each round had a different muzzle velocity, and therefore the computer had a different cam for each type. The computer would take the range data, merge it with the velocity data, and via a set of rotating shafts, supply this information to the gun's super-elevation mechanism, resulting in the gun being elevated above the gunners line of sight sufficiently for the round to overcome the downward pull of gravity on its way to the target. The gunner's sight however remained locked onto the target.