Originally Posted by
Loren
Good news and bad news.
The good news is that the car was mostly a joy to drive and has been trouble free, of course. The more time I spend with it, the more I learned its quirks, just like any car.
The bad news is that my first tank mileage was WAY off of the onboard estimate. And I'd worked so hard trying to hold onto 50 mpg on that tank that it pissed me off, and I just gave up on hypermiling it. The dash said 46.9 mpg, actual was 38.42! My initial fill must have been light, and my final fill heavy. But, to make the numbers work, the fuel would have had to be off by 1.1 GALLONS.
Hang on, I didn't do the tire size correction. And I just did a calibration based on the first leg of my trip. I noted actual locations throughout the trip. So, the first leg by Google Maps was 256.0 miles. By odometer, it was 245.5. The difference is right inline with the tire size difference, so that makes sense. I'll call it a correction factor of 1.04 for mileage.
That puts the corrected onboard reading at 48.78 (woohoo!), and the actual at 39.96. Would still take 1.15 gallons of fuel to balance that equation. Can't think of anything else. I didn't do anything weird. No EOC. No neutral-coasting. Just straight up gentle accel, limiting speed to 52 mph, and judicious extended glides whenever the circumstances were right. I had it up to over 52 on the display, but the last 30 minutes or so before I filled up, the road got really lonely and I opted to add speed.
Anyhow. The REST of my fill-ups, while the MPG was awful (for a hypermiler in a Mirage), were fairly accurate. These are corrected numbers:
38.8 actual, 38.3 displayed
37.8 actual, 37.5 displayed
35.6 actual, 36.8 displayed
37.4 actual, 37.8 displayed
So, the trend is that the display is typically within about 1%, which is pretty good. I'd bet that the display is more accurate, and the error is in the fill-up. These were all partial fills. (I did a lot of late-night driving last night in very out-of-the-way places, so I filled up early to avoid getting stranded) 5-6 gallons. 1% of 5 gallons is .05. I'd be surprised if a typical fill, even on the same pump is consistent to within a tenth!
Yep. Gave up hypermiling for this trip. Just went for having a little fun, learning the car more, and "getting there". Throwing out the first tank as questionable, the rest of the trip has an overall average of 37.95 mpg. Considering I opted for a cruising speed that was typically 65-70, and was just out having fun, I guess that's not too bad.
I did notice pretty early on yesterday that just like my 5-speed, MPG takes a serious dive after about 60 mpg. The sweet spot if you want to keep 50 mpg is to stay below 55. The average will keep slowly ticking up as long as you keep it below that. As soon as you edge up to 60, it starts ticking down rather than up.
I also noticed that my initial thoughts about the CVT "coasting better" than the manual were wrong. It's still dragging the momentum down when you take your foot off the gas. Maybe not quite as much as a manual, but it's not free-wheeling like I thought it was, either.
Don't know how this fits in with hypermiling (probably doesn't), but I did adopt the "use sport mode for acceleration" tactic today. For acceleration. For keeping up with fast-moving traffic on hills. For just general "responsiveness" when you need it. Slap it in sport mode. I don't think it gives you anything you couldn't get by just mashing your foot to the floor. But, you do get more control than that. More responsiveness. I like it.
The car handles better than it has any right to (with good tires under it), but I think the rear shocks are near dead after 25k miles. Very wallowy back there. But, after about the first 6 hours, I got used to it and learned to work with it. I did put the rubber spring spacers on all four corners. They're not quite active at static load, so they won't affect small bumps. Bigger bumps will engage them, I suppose (I'd have to do some serious back-to-back testing to really tell). And when you roll into a corner, they will engage after about the first half-inch of body roll and firm up the spring rate a little bit. (I calculated how much... but, then I forgot... whatever cutting out one coil does) So, this setup probably isn't rolling quite as much as stock in a turn, and the second half of the roll is slightly firmer. If the rear shocks didn't suck, it would be great!
I've got probably two more fill-ups before this trip is done. I may or may not bother tracking them. I think I've learned about all I can from this trip, and I'm not likely to have time to do any more proper hypermiling.