Shell V-power nitro+ VS plain old cheap petrol - My experience and thoughts

grungebob

ICBM said:

So what gives the measurable difference in mpg then?

After a cheap supermarket opened near me, I tested it over an average thousand miles on both types, twice for each, and the difference was consistent - the supermarket gave worse fuel economy by a noticeable amount (about 3%).

What kind of lab test? A full chemical analysis showing all trace compounds, or a burn test to show energy content?

Very very difficult to do trace analysis on essentially a heavy mix of hydrocarbons particularly as all easily soluble in each other. Best you could hope for is a breakdown of active groups unless you know specifically what your looking for from the get go

the difference in economy will come down to the purity of the finish product. Just because both octane ratings on comparable mixes are the same doesn't necessarily mean contaminate levels are.