failure of hypermileage techniques?

Quite simply put, driving the Prius like a grandma gives you worse mileage then if you were driving like a bat out of hell. It is very counterintuitive. You dont have to hold up traffic, just drive it and your MPG will more than likely improve.

If you want the best mileage, then practice pulse and glide.

 

I strongly disgree. It is quite the opposite and not counterintuitive at all. Driving "like a grandma" will never give you worse mileage, as the ICE is not being activated as frequently or soon. I'm not saying drive slowly, it is more important to be consistent. You don't drive to please other drivers - you drive to get from point A to point B safely.

Now to the OP, my biggest guess is that it's the cold weather. In colder weather the ICE will stay engaged for longer, which is exactly what's happening to you. I've experienced this before too, it drove me crazy. Members here typically report a reduction of 5-10 mpg during the fall/winter/spring. Also, check your engine oil level. It might be overfilled, causing the engine to work harder to pump the extra oil. Finally, you probably already know this but be aware of slopes while your driving; the slightest downgrade can yield 100mpg even at 45mph. Again drive consistently, bringing your car up to speed and then letting up to shut off the ICE.

Don't be discouraged. I'm still strongly betting its the cold weather. Seldom is there something wrong with the actual electric motor. Continue to focus your efforts on the instantaneous consumption while paying attention to your speeds and conditions of the road. That is the best way you can improve for the long run.

 

By "driving like a grandma" I mean accelerating extremely slowly as you do with a normal ICE only car to get better mileage. The OP says the cars he used to drive, he drove to get much better than normal mileage. This probably means accelerating really slowly to speed combined with good techniques like keeping speed for stop lights and traffic.

In the Prius when you accelerate very slowly you're using the electric motors only to a certain speed. This drains the battery, which then needs to be recharged by the ICE which is very inefficient, meaning reduced MPG over the long run. By driving with a more aggressive acceleration approach, you are limiting the time the ICE is on. The battery keeps most of its SOC, and the ICE runs really poor MPG for a few seconds instead of running slightly poorly for a really long time, or the way the OP is driving, not running at all for a while and then extremely poorly for a long time.

I am suggesting the Pulse and Glide method which works extremely well, in addition to the coasting with no arrows and anticipating traffic lights/traffic.

This is what I mean by counterintuitive. Most people (including myself) ran the car in electric only mode for much longer than it should have at starts because I thought it would improve milage. It did not, and will never be better than normal driving or driving craziliy in the Prius.

 

I know want you're talking about now. The pulse and glide method works, but to a certain degree. You really have to know the road you're driving and find the sweet spot to let off.

Oppositely it's possibe to very very slowly accelerate from a stop without ever engaging te ICE (when it can be done) and i disagree that this would waste more gas because the energy or gas required to recharge the battery is far less than the gas expended during pulsing. But yes pulse and glide is far easier to drive in real world situations.

 

Weather, road conditions, all have a major impact on the Prius.

For instance, temps were in the low 60's, Drove from Seaside Oregon to Longview WAshington, which, by the way is uphill to a slight degree, Seaside Oregon is right at Sea Level where we live give or take a few inches during the tides.

Set the trip meter, and drove to Longview Washington, roads were dry, no wind noticed, temps in the low 60's.

Arrived in Longview with an indicated 62+ MPG.

Left Longview back to Seaside Oregon, same identical road. However a cold front came in and temps dropped into the 40's with heavy to moderate rain.

Arrived at Seaside Oregon after reseting in Longview for an Indicated 50 MPG.

A true difference of 12 MPG just due to weather, road conditions.

alfon

 

I've found that what works for me is "egg" to ~10 mph (electric only) followed by "normal car driving" acceleration (read, brisk). Anticipatory gliding when I see traffic slowing or a changed/red light ahead are also key. I only keep 35/33 psi in my tires, and commute 75 miles each way everday in hilly N. VA. I'm averaging 54-55 since warmer weather kicked in, and have a lifetime of 53 since Aug 09 (26k miles). I broke myself in with Eco mode, and have since switched to Normal unless in stop&go during bad beltway rush hours.
FWIW, I would consider dropping the tire pressure so you have more confidence in corners/curves and can likely maintain a higher, more constant speed. Try driving "near-normally" in Eco mode and see what that does for you. I found that often my mileage would suffer when I tried too hard to hypermile in our hilly region, and definitely wasn't worth the leg pain (Prius Foot). hope this helps.

 

Another thing to add on is how long our your routes? Thats one thing with me that kills my mileage. Also moderately long stretches at around 55 then stopping and re-accelerating. Throw a hill or two in there and it kills my MPG. I guess for accelerating I use the "grandma" style and glide EVERY chance I get. With some experimenting with other techniques this is the most effective for me. I think you will have to determine what hypermiling techniques are best suited to where you drive.

 

i drive 7 miles each way to work each day, half rolling hills30-40 mph and half highway 55 mph. i drive like a grandma and use p & g. in nice weather, with no heat or a/c, i get low 60's. if you do this in a 2010, i would expect even better. shorter trips will hurt as will other factors. the car itself? hard to know unless you can try another or someone else tries yours.

 

Low 60s is excellent, in the 95th percentile.

 

To choose between a 2010 Insight, A 2010 Golf TDI, and a 2010 Prius to replace my 2000 Insight with 261,000 miles and LMPG of 62, I devised a 26 mile route involving stop & go, Highway run and a hill climb of about 1000 ft and subsequent descend to the start point. Result 2000 Insight 5 spd = 66 mpg, 2010 Insight = 54 mpg, Golf = 48 mpg, Prius= 64 mpg. The Prius is capable of very good MPG! To almost MPG equal a 1800# car running a 1 liter 3 cyl with a standard tranny, with a 3000# car running a 1.8 liter engine and an automatic at that and including all the safety gizmos added over 10 years is pretty darn good. Ted

 

it's definately the grandma technique!

 

that's an excellent study, should be a sticky for people trying to decide what to buy.

 

Hi All,

Egg on the peddle is intended to avoid fuel system enrichment needed to keep an Otto engine from stalling in standard cars. The Prius engine is running at 1000 RPM already, and it has MG2 for all the take-off torque, and it really takes a heavy flooring to get the engine into enrichment. In city and suburban secondary road travel, normal traffic its not going to happen. Accellerating with about a 1800 to 2200 RPM engine speed for the 1.5 liter PRius engine, (probably less 1450 to 1850 ? for the 1.8 liter engine) turns the least amount of gas into the most amount of car speed. If you egg-peddle a Prius you will operate the engine below its best efficiency range, or less than 1/10 max power. My experience in the Gen II Prius a 42 to 35 mph P and G on flat road gives 74 mpg for the cycle

Now, that is the car system issue.

There is also the roadway system issue to deal with. If you are in traffic, and cannot properly use the energy you stored in the vehicle speed during a pulse, by gliding out until the next pulse, or down to 15 mph at a red light, then even the most efficient use of the engine is wasteful. And you can get better mileage in these situations by lower power accellerations...

Finished the week at 66.3 mpg....

 

How has this thread suddenly brought out all the hypermilers?

 

66?!? i'm jealous! do you need a scan gauge for the rpm's?

 

we want everyone to get great mileage!

 

i think you're wrong on the instantaneous mpg. i'm always surpried how low it goes when accellerating. forget that and watch you're power flow. accelerate moderately to a little over your desired speed and back off the pedal until there is no powerflow. this is p&g and should reward you with good mpg. but measure it on full tanks only, not by trip. if your tank averages are going down as weather gets better and your driving environment is similar, you may have to look at the car itself. but give it some time. what are your tank averages so far?

 

Why do you say that? Looking at your speeds, take a look at http://www.consumerreports.org/cro/...-fuel-economy/best-and-worst-fuel-economy.htm. Look at how well the most efficient non-hybrids did in their city test. We're not talking about instantaneous fuel economy here, we're talking how well it did for their entire city test.

Reread the early posts by 2k1Toaster. You're probably driving it wrong by doing things like trying to accelerating very slowly in an effort to keep the ICE off. Bad idea.

For speeds between 25-40, you should do pulse and glide.