back to basics-cams, compression, and todays fuels

[axam48ida]

I am toying with one of my daily driver motors. 69x88 with dual 40's and 110 cam. this motor has plenty of
power to comute in but with todays gas ....what is the lowest one can go either in a stock motor or cammed motor where
it begins to hurt you. low compression is great for todays fuels but there is a point where the lack of compression effects the efficiency and driveabilty? the 69 x 88 with a cam and lightly ported dual port heads has gotten better mileage than some single port 1600's  the 69x88 is tired and still squeezes 27.5 to 30 the 1600 with stock cam did it's best at 27.5-28.5. that's with a taller rear tire on both engine runs. The additional torque and power aids in the mileage. I am just trying to figure how to squeeze that 35-38 mpg out them. It's a 63 bug with a roof rack that takes 1-2 mpg away (yes that much)
Any thoughts about the original question???
  Reading over the mpg motor in hot vw's   I thought of going with a bigger stroke ...say 74 with 88's or stock bore.
then thinking about this I have a 74x94 10.5 to 1 motor in my oval and taking it to LA  or any freeway driving I got up to 28 mpg on the hiway. that's with 48's and 37mm venturi.
What's the best combo???
 sorry for the long post.....

[The Ideaman]

Steve Hollingsworth built a mileage motor for the Berg Cruise '06, 80mm DPR custom stroker crank and 85.5 pistons running with Kadrons.  Steve said the engine is a millimeter shorter than a stock 1600.  He also said it makes something like 98ft/lbs of torque @ 2800 rpms and doesn't rev over 4300 rpms.  Before getting up into the higher altitude, somewhere from Phoenix to SoCal to Mesquite, NV he said he was averaging about 34mpg and this is in his '69 Beetle w/ Berg 5 (4.12 R&P, 0.82 (bus 4th) for 5th gear) car fully loaded for Steve and Deena Reese and luggage.