Jay Garrick is underrated powerwise

Jay Garrick, for those who don't know is the Flash of the Golden Age of Comics. Due to a lab accident he accidentally activated a metahuman gene within him, giving him the speed of Mercury.

A lot of people downplay Jay Garrick on the basis that he is much slower then Barry Allen and Wally West. And while it's true he's not as fast as those two, Jay is quite a lot stronger then I hear some people. I've heard some people claim Jay Garrick is "only" lightspeed and that in terms of raw strength/durability he is only street level. However this is untrue. 

For those who don't know DC Comics Speedsters are ranked based on what "barrier" they can break. First is the sound barrier, then the light barrier, then the time barrier, then the dimension barrier and finally the ultimate one; the speedforce barrier.

Jay Garrick WAS lightspeed when he was first introduced, in fact VERY consistently he was stated to be lightspeed.

However this was just the speed of Jay Garrick when he was first starting out.

Later on Jay Garrick was fast enough to equal the speed of Post-Crisis Superman and was able to outpace him once he started using speed steal on the Man of Steel

and Superman was fast enough to rival Professor Zoom's speed

Professor Zoom being one of Flash's fastest villains, enough to somewhat stalemate Wally West in the Post-Crisis era after he stopped limiting himself

Jay Garrick was also fast enough to converse with Wally and Bart in nanoseconds or billionths of seconds

He was also able to keep up with Superboy Prime

For reference Superboy Prime was fast enough to punch past the dimensional barrier while weakened

The Dimensional Barrier being the last speed barrier before the speedforce barrier itself!

Superboy Prime is also a Pre-Crisis Kryptonian which were infamous for nutty speed feats, to the point Pre-Crisis Superman could break the time barrier as a child

This is all consistent with what I think is Jay's best speed feat, running up to the edge of the speed force

Consider for a moment that Wally West's famous "Trans-Time" speed feat was back when Wally WAS deliberately holding back and was only implied to be past the Time Barrier.

Now for the record I am NOT saying Jay is equal in speed to Wally or Barry. Just that he is undoubtedly MFTL and a lot faster then people think, being nigh-speedforce level speed.

In terms of power, while Jay Garrick never learns the Infinite Mass Punch per se, he does have the abiltiy to use his speed energy to absorb kinetic blows and to deliver some of his own. He's been able to fight Black Adam

Black Adam being able to tank punches from Superman

Jay was also able to harm Mordru with his strikes, though as Mordru is magic-based and given the caption it may just be that Jay is not giving Mordru time to use any defensive magic

That said even when taking off-guard, Mordru was able to take a punch from Pre-Crisis Superboy

Anyway, that was just my quick blog on Jay Garrick. I hope this convinced you he is far above lightspeed and street level in terms of physical power.