Sounds fishy to me, stepping on the gas to start a fuel injected car
does nothing to help it start unless it was throttle position. I've
used regular in my 2004 and saw no difference in the starting. What
does Paul say, (C4C5)?

The grade of fuel you use has nothing what so ever to do with the way a car
starts....the C5 cars have been known for fuel pump problems..and at 27,000
miles it is not unusual to have to replace the pump....I would look to buy a
350Z or at least something other than a vette...you already have problems
and you have not yet even purchased the car..be warned!!!!!!!!!!!!!!
problems like you describe have a history of never going away....walk away
from this one NOW !!!!!!!

Is there any pattern of occurrence?  Hot engine, cold engine, how long
between shutdown to start attempt, parking angle, other screwball
things? I can recall a starter on a '79 Pontiac that would hesitate
after the first couple of revs of a warm engine and then speed up and
start the engine.  It failed within 6 months.  Extended cranking may
also point to a dry fuel rail or low fuel pressure--what happens at WOT
in 4th at 85 or 5th at 120?  Or, something similar if it's an auto?  Oh
yeah,  what's battery voltage doing while all this fun is happening?

I think it's hard to blame regular fuel for this problem but offer the
following story if you want to embrace the octane rating idea.

Back in the '50s, Mobil Oil Company (then, Standard of NY) used to
sponsor an annual gas mileage contest out of L.A.  Current model year
cars, about 1500 miles R.T., mileage measured in "ton miles per gallon"
-- gave Caddy & Packard a big advantage over Chevvy, Ford & Nash.

Contestants could gas up with either "Ethyl" or "regular."  Most car
makers chose to use "regular" to emphasize economy.  One year, I recall
that one of the biggies (Lincoln, Packard or Cadillac) chose to use
Premium, "not because we needed it but because it would give us quicker
starting."  It's also possible that winter premium, aimed for very cold
climates like Alaska or northern Canada might have some quick-start
additives. Probably not in the lower-48 in April though.

About once a year, I run a half-tank of regular through the L-98 and
think I feel some mid-throttle combustion roughness--feels "lean." It
seems to say, "don't do any WOT with this fuel."  Tail end of the tank
gets a shot of injector cleaner then it's back to premium.  I've never
had extended cranking or cranking hesitation with regular in the C4.

Right now, West Coast fuel is so variable from tank to tank--seasonal
changes, special blend changes for Katrina, ethanol, no-ethanol, MTBE,
no-MTBE, wide variations in feed stocks w/aromatic additives, etc. that
it would be hard to judge anything--just thankful to have a steady
supply of any go-juice.  Commuting in the C4 uses about a tank a week
and I sometimes notice what I think are tank-to-tank changes in
premium--odds are that its climate change differences with an ancient
design of ECM and fuel injection.  It's harder to judge possible fuel
variations in the C5 since I don't drive it as often and it gets filled
up at two or three week intervals.

Right now the C5 is the weekend fun car and I don't want to be forced
into taking it easy on the pedal.  When the initial fun wears off, I
might try a 1/2 tank of regular.

Gotta go saddle up and earn a buck.