Prius Actual Gas Mileage VS Advertised

Bob's chart jives with my experience in steady state driving not pulse and glide.

 

BW uses cruise control for reproducibility. Other drivers with P&G data are clearly labeled. In any case, there is no such thing as P&G above ~ 42 mph in a G2 Prius, or ~ 45 in a G3 Prius.

I looked at one of the reports. Typical distance driven in 15 miles. Bob collects data on warm days, no AC used, and engine warmed up. Apples to Oranges comparison.

 

Well the question really is what would another comparably sized car do at 76MPH ...

also if you want better mpg go around 60MPG and see I bet you will be around 49/50 or even higher let assume you drive 100 miles of your commute at this speed difference would be 20 minutes longer commute for the approx 3mpg extra not sure or about .10 gallon of fuel ..

by the way is the 46mpg is calculated or just what the computer tells you (it lies +5% so real number 43.5/44)

 

Remember that the EPA mileage is based on using SPECIAL 100% high-octane gasoline which is NOT available to the public. This gasoline has ZERO alcohol.

Publicaly available gasoline has alcohol added. The alcohol lowers the energy content of the gasoline.

This is a big reason the EPA mileage is so much higher than can be achieved without hypermiling techniques.

 

Your conclusion is incorrect. The EPA sticker is quite a bit less than the fuel economy actually obtained. The downward fudge is meant to correct differences in the test from median street driving conditions and driver behavior. So the ethanol content, amongst many other variables, is taken into account.

FYI, E10 has about 97% the heat content of 'pure' gasoline. If all else was equal, E10 use would drop fuel economy about 1.5 mpg. You should keep in mind that since the EPA single number on the sticker is meant to mark (I cannot remember for the moment) either the 50th or 67th percentile of the population, we EXPECT that a large number of drivers will report less than EPA fuel economy.

 

The wife and I drove down to St. Louis, MO yesterday to pick up my "new-to-me" Prius yesterday. It's a 2010 hatchback with 27,550 miles.

It didn't have a completely full fuel tank when I left the dealership, but the computer said I got 52.5 mpg for 185 miles on the trip bringing it home. Even with a 4% error, it's still 50. Needless to say, I am thrilled. Drove 68 to 69 mph (speed limit was 65) and only used the cruise control on the long flats.

 

That sound about right !! if you keep slightly under 65 (in my experience about 60 is the sweet spot for mpg) you could get even higher ... make user you check your tires ... dealer ship always under inflate ... my brand new had 29 and 30 front !!!and 25 back ... it felt like a boat ....

 

Ha! You got that right. I checked them this morning and they were 33 all the way around. They have already been inflated to max pressure (44) as stated on the sidewall.

As an aside... I've always run my tires at max cold pressure. Been doing it my whole life. Don't know any other way. I've got high pressure "ambulance" tires on my full-size, all-wheel drive Chevy Express van. Those tires take 80 psi. Good thing I've got an air compressor in my garage!

 

WOW once I was right ... I run 42 front and 40 back ... (just a tiny bit conservative) but I was totally suprised... I had a 10 miles trip to home and I couldn't figure why it was such a different btw the 2010 which was lost during Sandy, the new 2012 which otherwise almost identical ...

tire pressure makes a difference not only with mpg but driveablility ... it felt I am sliding off the road but of course it was the opposite tires were grabbin the road more ... but sure felt different.

 

I am crazy about our new 2013 Prius 2. My wife says she would have done anything to get one sooner ifs she had known how much safer my driving would be. I am still learning the tricks to increase my mpg. After my last fill up fuelly.com (great program) indicates an average of over 52 mpg. This was before I increased tire pressure by 5 psi. All of the driving has been around town with many very short trips of 1 to 2 miles and an occasional freeway trip of 8 to 10 miles. Weather and terrain are both ideal in SE Florida. The highest point in all of Florida is 344 feet above sea level and winter this year was on a Tuesday.

 

By the way, what is the best compromise on tire pressure? My wife thinks "road feel" is highly over rated and I want great mpg. What should I use? I am now at 35 psi all around.

 

In mild climates and using the OE tires I feel something between 38psi and 44psi is a good compromise between comfort, safety, tire wear and fuel economy. When it gets really hot here in NorCal I run 46psi or more because the roads and tires become more flexible and I can get away with higher pressures without ruining the ride.

For most tires in our size, anything over 45psi starts the point of diminishing returns unless you are serious hypermiler and have smooth roads.

On very rough roads I would stay below 40psi unless temps are over 95F.

 

I think it's best to run 2 pounds differnce, like 40 front 38 back. I think it makes the car track better.

 

Thanks to both of you. That helps.

 

Sorry for not being clear. When I state a pressure number I assume that is for the front tires and the rear will always be 2psi lower.

 

I run 42 front 40 back that seems to be OK for three different priuses...

I would increase by 2-3 psi for a week and see .. there is some noticable differnces both driving and riding .. only you can decide BUT for better MPG you would need higher PSI ... (in general)

 

MPG....this morning driving 35 mph and coasting on the hills. At 5 am no one is on the road but you and darn deer...I hate deers!

SCH-I535 ? 2

 

When I was in Reno NV last summer on vacation I used a tank of regular non -ethanol gasoline and I noticed at least
a 3-4 mpg increase over 10% Ethanol Blend.

 

That's nice, but try not to read too much into a single tank. I see that much variation from tank to tank using exactly the same blend, and traveling the same routes LOL