At the present time,I have Marathon plus tyres on my SWB recumbent.20 x 1.35 front,and 26 x 1.35 rear. I would like a set of lighter,faster tyres.I am considering the marathon racer,or the durano`s,or Kojaks. Or are there other options that are suitable?,
Terry

Placebo effect has value ..if you think it will make you faster will you push harder to prove it?

Durano and Kojak are certainly lighter and aimed more towards going faster but that doesn't guarantee anything.
I have a reasonably light 20x 1.35 Primo comet and a not-so-light 26 x 1.5 Primo comet kevlar on my SWB. Both are lighter than the Marathon Plus, though. Which doesn't guarantee I'm riding any faster than you are.

you could all be right,I used to have primo comets,and its not noticeably slower now with marathons.

Tire weight is almost completely irrelevant.

Rolling resistance is not and can make a huge difference. Basically you get to choose between speed and puncture resistance.

If you put kojaks on your bike, you'll definitely notice (my 26" average speed went up over 1 mph)

Tire weight is almost completely irrelevant.

I thought rotating weight was 5 times worse,bike still goes well on plusses though.

Tire weight counts up to twice when acceleration, but not when riding at a constant speed. When you compare the differences in tire weight compared to the rider + bike + wheels, you'll seer that your talking about a very small percentage.

Changes in rolling resistance can be much much larger.

I have been using Racers for awhile and like them. Light, fast, supple ride, minimal rolling resistance and descent flat protection. If you search around you can find sale prices. Good all around quality tire.

I found them on sale at Spa cycles,on of my favourite suppliers.Do you use the folding type?.