Yes. mine was set to 1440 by default. I find an MTU of 1492 is the sweet spot.
As low as 1440 is odd, but 1492 is the number used on shared wired networks (such as BT wholesale) where the connection is shared with other customers and needs PPP around your data flow. The Ethernet (and also used on WiFi) default is 1500.
This is why you should leave the router at 1500 and change on the computer:
Your computer will send packets of 1500 bytes and they will hit the router, whereby the router itself has to hold on to them, cut them into 1492 or 1440 size units and send on.
Your computer has a lot more speed and capacity than your router, so because it is so busy cutting these packets of information into smaller sizes, it is throwing away speed.
If you change the MTU on your computer, then your router has to do nothing but forward the smaller packets to the network, something it can do very quickly.
20 years of broadband connectivity since 1999 trial - Live BQM