Engine won't turn over

Vehicle receives regular maintenance. Ran great yesterday. Today, engine tries to turn over and it won't catch to start. It is not the normal "clicking" of a dead battery, it makes the regular sounds, it just won't start. I'm having the same problem. On cold mornings it will usually start after a couple unsuccessful cranks and pauses. Dealer worked on it w/no resolution. Recommended "dry gas" fuel additive. That worked initially. Then symptoms started again recently. We use almost exclusively 87 octane gas from wawa. Which I believe is a 90/10 gas/ethanol blend. Could that be a culprit? Any help would be appreciated. Any ideas?