Is there much difference in mpg when you run like a 2.02 valve compated to a 1.90 valve? Like comparing the edelbrock performer heads with the 1.90 valve instead of the 2.02 is it going to make a bit of a difference?
We are talking about a Stang with .......
all the hot rod parts in place like heads, cam, intake, etc
all supporting parts in place and functioning properly
no issues such as vacuum leaks and the like
Simply Put ... Typical NA Street Combo
Driving Conditions Next
Cruise down the highway
and
Not ... driving around town
To many variables in around town driving :Word:
Mostly ... a heavy right foot
Tune Last
If you got all your hot rod parts installed perfectly and all other things
in good shape but you are still running on the unmodified pcm
Your tune is gonna be off a good bit
You just can't expect to be making around 300 rwhp without flowing
MUCH MORE air and fuel
The pcm has no way of knowing this
and
No longer is it as efficient as it once was
When things were stock at obtaining the most power
for
The least amount of fuel used
Here is the deal about a Custom Tune many don't consider
You change the values in the pcm to reflect what needs to be changed
due to the addition of all those hot rod parts.
Sure ... everybody can see you do that to make more power
BUT ALSO ...
You do the Custom Tune Thing to bring back in line the pcm's ability to
use its Closed Loop programming to make the best use of fuel at any
given moment in time when you cruise (non wot) around town.
Bottom line is ... WAY MORE ... to Tuning than just ... WOT :Word:
I've gotten over 19 mpg at a cruise of 75 mph avg on short trips
so
Its no stretch of the imagination to expect more at the speed limit
Now Summing Up
Does it make sense the valve size would have no bearing on fuel use
during a cruise as the pcm can find the optimum use of fuel