Yep - maybe, maybe (probably not) this was different with carb engines, but ... and, then only at maximum flow (full throttle) ... again, maybe ...
Great marketing by K&N, though ... Goldman Sachs owns K&N (2016) so ....
I'm not sure anyone could tell any difference between 0W-20 and 0W-30 - at any temperature even if starting really cold with both still 0W ... "a few MPG" difference is just not possible. It's even illogical.
I had one removed yesterday - I had asked AI to do the math on something - I guess even that sort of AI (vs AI from using a calculator) is not allowed.
True, all things being equal - and real world city driving cannot provide this ... so, any huge change (like 10%) is simply because the real world city driving differences caused it. "I am not in a controlled environment ..." - exactly.
A controlled environment test will not change by 10%...
Again, nah.
Simply too many variables in city driving ... you are way outside the 0.5-2% expectation ... even if extremely cold wouldn't expect that much difference.
Old post, but a "few mpg" would be in the range of 10% or more? Just from a slight increase (somewhere between 20-30? I don't think so. "A bit of lag with the engine?" Again, I don't think so. Placebo effect?