Using a higher octane on Honda Civic to improve fuel economy and efficiency?

Regular work just fine. Your friend is ignorant.  Go to any Chevron gas station and get gas with Techroline in it and it keeps everything clean.  Also do more than just short trips.  At least take it out for a 50 mile burn on a highway doing highway speeds and come back doing the same.  There, you cleaned it out from the short driving you do in town all week.(driving a block here or there and then shut it down for the day.

. If you are driving farther distances than in town(like some highway) then there is nothing you can do except stop tailgating so you can drive at an even speed.  55 is the most economical speed to drive at.(53 actually)  I have tested it on trucks, cars, motorcycles of all makes carbed or fuel injected with radial tires at proper tire pressure and not green light race off the line nor tailgating. loaded or unloaded.  The economy always worked out the same.  It has to do with wind resistance.

Your car won't really get any benefit from using higher than 87 octane fuel .Maybe the accord R would benefit But a basic honda won't benefit too much May even have higher temps since higher octane fuel burns at a higher temp rate .Unless it's specified by honda ITS 100%UNECESSARY and you won't see any real gain as far MPG or even performance gains .So don't waste your money 

Waste of money...................

No. Unless you  put on an electronic tuner to advance timing, no advantage. For the same brand of gas,  there is no difference in "Quality" nor  "cleaning " of Premium over Regular.

bax: All cars Have  fuel filters. If not in line or in carburetor; in Fuel Tank. Get A Clue..

This myth simply will not die. Your friend is 100% wrong. Octane has nothing to do with fuel economy or efficiency. Putting octane higher than 87 is a complete and total waste of money. It will provide no benefit whatsoever in your Civic. 

I think your Mom and Dad will confirm this. Friends always know things and their advice needs to be adhered to. So of course. Listen to your friend. 

A type R will probably benefit from premium fuel, no other models will.

I don't agree.  Use the gasoline your owners' manual recommends.  Paying for more expensive gas just wastes money.

It's a waste of money buying high octane/premium gasoline if it is not required. All gasoline is highly refined which is why many car manufacturers don't put fuel filters in their vehicles. The higher the octane the more inhibitors in the gasoline to keep the motor from having pre-ignition problems. Another words low octane gasoline has less inhibitors in the gas and therefore burns better. Your friend is not so smart.

  Octane has nothing to do with cleanliness nor efficiency.