Took my new 2011 Prius on its first road trip from Long Beach to Las Vegas (about 290 miles each way). Strange mileage issue: on the way to Vegas I got 51.7 mpg driving 74 to 76 mph most of the way, using cruise control. But on the way home I got 42.6 mpg. Again, drove 74 to 76 mph most of the way with cruise control. Same driving style. Same type of weather both trips. Only real difference were some fairly strong crosswinds and headwinds on the way back. But is that enough for me to lose 9 mpg on the way home? Checked tire inflation and it hasn't changed. I just don't get why I lost mpg on the way home?? Any ideas? Ps -- before this road trip my driving has been up the 405 freeway in stop and go traffic. Definitely seems that is where the car shines -- been averaging 57 mph while commuting back and forth to work for the past two weeks!
Yes, the Prius relies heavily on it's low aerodynamic drag to achieve good highway mileage. A head wind causes an obvious increas in drag, a cross wind means your car is flying diagonally through the air and your 0.25Cd will take a real big hit.
Absolutely. And for a Prius, crosswinds are even worse than headwinds. I haven't yet characterized my Prius in strong winds, but wind made a huge difference in the previous two cars. A strong tailwind on top of hypermiling once helped push my Subaru wagon eastbound across my state at slightly over 39 mpg. While that car was regularly getting 32-34 on the highway that summer (low speeds due to $4.50 gas), I wouldn't have expected over 30 westbound into the wind that day.
Will you get better mileage left to right or right to left? I think hard uphills, gentle downhills gets much better mileage than gentle uphills with abrupt downhills.
The hills on the way home is a lot steeper then when they are going. I ended up somewhat similar results. The hill right after stateline is a lot of work for the Prii.
Yes! It's that damn wind. I got 55mpg going to Vegas from Palmdale, driving 70mph. And then I would get 40-45mpg on the way back.
You've got to remember that you also got benefit from the wind in the opposite travel direction so its really only half the difference. We always get much better mileage going to Albuquerque from CA than the opposite direction. Primarily because of the prevailing winds.
I think your mileage is very consistent with the speed you were traveling at. Averaging the round trip (both ways) you got 46.7 mpg. Now give or a take a few MPG here and there for stops, and energy lost on braking during descents. You probably ran with the A/C on, and with the headwind / crosswinds, it shows. Also remember that the Prius is only supposed to get 48 mpg on the highways.
What makes this weird is that you are going from sea level (Los Angeles area) to 2000 feet for Las Vegas. Also, the prevailing winds are from the Northeast. All means that you should get better MPG going to Las Vegas, not from there. So the only explanation is the change in wind direction (other than temperature difference, but you say it was the same weather both trips). Mike
yea...i always get 53-58mpg on the way to vegas from LA even with the AC set at 73 the whole way then on the way back to LA i struggle to get above 40mpg until i get closer to LA....all in all though, my roundtrip still averages out to 50 mpg....so vegas and back on one tank of gas($40-45). That is truly amazing. Be happy with that
To gain 2000 ft of elevation in a Prius requires (best case scenario) 0.2 gallons of gasoline. Over a 290 mile trip, if flat terrain gives 50 mpg, the gain in elevation results in about 48.3 mpg. Given non-ideal conditions you may burn more gasoline (perhaps 50% more), so we can calcuguess that mileage will drop 2 mpg on the way up. Mileage will correspondingly increase 2 mpg on the way down. Averaged over the entire trip it will wash out. I drop and climb 800-1000 feet every over a much shorter distance and it's crazy how different the climb and descent mileages are.
I agree with you, but the OP's numbers were in reverse. He is getting better MPG though climbing in elevation (as small as that climb might be). Plus, the general prevailing winds would also be in his face while going to Las Vegas and to his back when going back to the Los Angeles area. But, again, he's getting better MPG going to Las Vegas rather than coming back. Mike
Oh my numbers were only for ideal conditions. As far as I can remember, the return leg ought to be fairly ideal though. So I'm a bit stumped. As far as I can remember, I don't have to downshift or coast much even going downhill on the way back from Vegas. This is in a conventional vehicle as I've never taken my Prius to Vegas. You'd only have to take your foot off of the gas pedal if the downhill grade is more than 3-4%, which is a lot for a freeway, and I don't think it ever gets that much.
I commute daily from Seal Beach to Hollywood. Often get over 60 mpg on drive home when using Harbor freeway.
Yep, I'm still a bit stumped on this. But it seems others going to Vegas are experiencing the same type of mileage so I'll be happy.
