A Little Perplexed....

As you know, I recently had the 120k service done including replacing belts and the 12v battery. After that I performed the Prolong battery conditioning. I've been pleased with the first couple of tanks afterwards, 47 and 46 mpg, but yesterday left me scratching my head a little bit.

I filled up at my regular ARCO station and headed to State Line (183 miles each way) to play golf. 72 mph almost all the way with the a/c on. Mileage screen showed 46.8 mpg when I got there. The car sat in an average of about 105* heat with the windows cracked, the rear curtain pulled and the reflective shield in the front window. It was between 113* and 120* all the way home. The screen dropped a bit, showing 45.8 for the round trip.

It was down to two bars on the gas gauge so I went straight to my trusty ARCO station, even happened to get the same pump. Filled it up to the tune of a calculated 40.6 mpg! I've never had that big of a discrepancy from the screen before and that's worse actual mileage than I was getting in similar conditions before.

Two things:

1. Would that 5 hours sitting in that parking lot heat really have killed the mileage that much? If so, should it recover on its own?

2. Is it most likely that the prolonged heat wave and then that extreme heat sitting in that lot made the gas tank bladder that much more pliable so it just accepted more fuel than it has been lately?

I'm wondering what is most likely because I probably won't have the opportunity to run all the way through another tank this week and we're supposed to leave for the East Coast next Saturday.

BTW, the car is in the garage with the windows open when here at home.

 

I know, I have a book on all fills since we bought the car last year. It just threw me that there was that much of a discrepancy between the MFD and the calculated mileage. Which is also what led me to think the flexible bladder is the culprit. I mainly wanted to confirm that you guys also thought it was the bladder and not the battery so soon after the reconditioning.

As for the golf, a friend and I play in Palm Springs and Laughlin all summer. We get to play some really nice resort courses for under $20 including riding carts and ice chests. The $12 Primm charged us yesterday includes bottles of water, GPS and free range balls at both the driving range and chipping practice area. The hospitality is great since they have to make sure the players staying at the Primm casinos who are paying through the nose for "stay & play" packages enjoy it and come back. Add to that the fact that hardly anyone ventures out in the heat and we have our own private courses with no one pushing us. The keys are staying well hydrated and parking the cart in the shade at every opportunity.

 

Mine is routinely overstated by one or two mph but it's never been off by five before.

 

No gas is ever added after the shutoff and I know true mileage is only realized over the course of many tanks but this was such an outlier it bothered me.

 

That was my thought too. Because it came so closely after the conditioning, though, I really feel more comfortable confirming things with people here. I have a lot of respect for the Priuschat members who really know the ins and outs of these cars.