10K MPG Check: Not impressed

I live in a hilly area with a short commute. It is not reasonable to think the car is going to deal with these areas in the same manner it does flatter areas. I easily get low to mid fifties on road trips with varied terrain and at speeds from town 25mph to 75+.

 

There's an entire thread devoted to measured versus the computer version of MPG on the Prius. Based on all the people who have posted their data, there seems to be between a 2%-5% difference, with the computer reading higher (better) mgas mileage, than what's actually measured when you fill up your tank. So that's nominally a 2 to 3 mpg higher reading.

That said...many of us easily get over 55mpg on their comutes. My comute is 28 miles each way, and my computer shows that i've been averaging about 32 miles/hour during my comute (because of traffic). I went an entire week, with my mpg over 60. This week, as I tried to increase my speed, I avergaed 58mpg. Still well above the EPA numbers.

Different strokes, for different folks. Personally, if i drove conservatively (to get better gas mileage), and I did not get at least the EPA number of 50mpg, I would have things checked out. Good luck.

 

i get and average of 53 for the last 8,000 miles, the computer on the car says 56.5. i drive mostly highway going 65-96mph I flow with traffic.

 

Your dreams were unrealistic based on your driving habits.
I bought my Prius planning to continue driving exactly as I have been doing all along and was originally happy to get 40 mpg. I am averaging 42 so I am very happy.
(exactly double what I was getting before...)

 

I think it has more to do with your most common driving routes than habits. I average 53mpg on the computer and I don't even attempt to hypermile, ever. But my routes to work, local shopping, and my family's houses are all very mpg friendly.

 

I'm sorry to hear that. I have 2,850 miles on my Gen III with a 59.2 avg (computer, not actual).

Bryan

 

I am only averaging 42 mpg and am wondering if something is wrong. My driving is a mix of highway/local and a friend who travels the same route is getting over 50 with her Gen 2.

I have a Gen V, which is loaded but I was getting better gas mileage when it was new. It now has a little over 3000 miles. Can anyone shed some light on this?

Thanks

 

Warm season is clearly better for me... 53.8 verses 51.3

Cold season is what I'm expecting to really see a difference with. This morning was the first frost. That hinted at good things to come.
.

 

* Realistically, that figure may not be attainable in your particular circumstance.

David (aka Blind Guy)

 

I am taking it to the dealer next week and will try to figure out what the issue is. I realize that 42mpg is better than 20, but I was expecting a bit more

 

What kind of checks have you done?

Try this: Verify tires are at an absolute minimum of 33 PSI cold. Get out onto the highway. Set the cruise. Reset a trip meter.

At 60 MPH, you should see dramatically higher MPG average. If so, there's probably nothing wrong and it's just your routine driving causing the lower MPG.
.

 

Normally we find a Gaussian distribution in any population:

	Column 1	Column 2	Column 3	Column 4
0	MPG	EPA ZVW30 (47)	PC ZVW30 (121)	07-09 NHW20 (284)
1	32.5	0%	2%	1%
2	37.5	2%	0%	6%
3	42.5	4%	6%	23%
4	47.5	23%	24%	36%
5	52.5	38%	40%	26%
6	57.5	28%	22%	5%
7	62.5	4%	5%	2%
8	67.5	0%	1%	1%

.
About a 1/3 achieve 52.5 MPG. About 1/3d are lower and 1/3d are higher. But we've only had the 2010 Prius in our hands for less than a year and the North American ones have yet to go through winter.

It is entirely possible that after a year, the ZVW30 and NHW20 will have similar milage. Winter is the season we'll learn the effectiveness of the exhaust heat recovery system. Wayne has already published some preliminary data and I'm hoping we'll see an update when the ambient temperatures are closer to 32F/0C.

Bob Wilson

 

Thanks - I'll give it a try...when I first started driving the car, I was getting over 51 mpg and my driving/route has not changed. haven't really done any "checks" per se - I wanted to do some reading here first and see what others are getting as far as mpg.

 

Studies with the NHW11 and NHW20 have revealed:

• battery efficiency - is at a peak for the first 3-4 months and then reaches a plateau for the life of the car. We've seen a short term improvement, 3-4 months, in mileage after traction battery replacement.
• transaxle oil - although still under study, it looks like an early replacement returns transaxle rolling drag to like new status. We just don't know how long this effect lasts, which is why it is still under study.
• bumper air inlet blocking - improves warm-up in the earlier cars and reduces cooling drag at lower temperatures.

The car is so efficient that most user modifications and maintenance are in the 1-5% range ... well within the MPG noise. It takes careful attention to detail to quantify these effects.

Bob Wilson

 

I've only had mine about 2 weeks, but find I'm getting 2 mpgs more this week than last. I think it's because I've discovered how to drive it more to still in the Hybrid Eco area.

How long have you been driving yours? Are you keeping it in the Eco and then releasing the pedal to get it into the Hybrid Eco Area once you achieve the speed that you want? Have you checked your tire pressure to make sure it has not dropped significantly? I have mine at 35 front and 33 rear. I think the model's V have a different recommended psi though..

 

How are 17" rims hurting if the tire diameter is the same?

 

I live in WV (hills) and am getting just barely a little better than you. However even at 45 mpg, I "am" impressed It's not what I had hoped for but with the low profile wide tires and a lot of highway driving making up most of our miles I'm satisfied. Had we not gotten the "V" we both may have a little better results. I do find that driving the back roads at 50 mph I can indeed get 55mpg. I just don't have the time to do that most of the time.