I could be completely wrong but, replacing the default tyres that came with the bike (Kenda K948, 700 x 40c) with something slick would make the ride easier?
I see guys with road bikes or other bikes push past me with ease while I feel like I am struggling. The only thing I noticed is the tyres, correct me if I am wrong.
On a completely different note, if I can replace, what tyre sizes should I look at?
I use this bike purely on road to commute from home to work
EDIT: Thanks guys for all the response @Criggie, the max psi on these tyres is 85