Even though the iPad Air is 20% thinner and has 24% less volume, and comes with a much smaller battery (32.4 watt-hour) compared to the iPad 4 (42.5 watt-hour), it offers the same battery life as its predecessor.

So far we’ve attributed this to iPad Air’s super efficient A7 chip, which is manufactured using 28-nm silicon chip fabrication process, compared to iPad 4’s A6 chip, that was manufactured using 45-nm silicon chip fabrication process.

There were also been speculations that the iPad Air also comes with an improved Retina Display as Apple has revealed on the iPad Air’s product page that they have managed to reduce the thickness of the display assembly, but it wasn’t clear what impact it would have on the quality of the Retina Display.

We now have a lot more information thanks to display experts over at DisplayMate. They’ve discovered that Apple has made significant improvements to iPad Air’s Retina Display that has helped improving the viewing experience, and in reducing the power consumption, which has made it possible to offer similar battery life as the predecessor.

DisplayMate who ran in-depth series of lab tests report the following improvements compared to the iPad 4:

• The screen reflectance has reduced by 23 percent, peak brightness has increased by 7 percent, and the contrast rating for the high ambient light has increased by 32 percent.

• Display Research reports that Apple has switched from a-Si amorphous Silicon LCDs up to a much higher performance IGZO LCD backplane. The switch to IGZO has improved display power efficiency compared to the iPad 4 by a whopping 57% percent.

• This also means that the iPad Air doesn’t get as warm as its predecessors.

All these improvements along with the efficient A7 chip seems to have helped in reducing the power consumption, and allowing the iPad Air to offer the same battery life as the thicker and heavier iPad 4, which is no mean engineering feat.

We tend to go by the headline features, and overlook such improvements, which is an incredible feat of engineering. So kudos to Apple engineers.