New to a Prius

[severedgein]

Alrighty, the Mrs. and I are finally picking up a Prius, she's got a 50 mile commute to and from work each day. It's about 90% highway (in that dreaded West Palm-Miami section of I-95) and I'd like to get her down to a gallon and a half of gas for that 100miles each day so she's only spending $5 a day on gas (oh what a dream!).

Without spending 3 days searching the forums, what are the best techniques Prius owners have found for reaching that 60mpg range?? Thank you all!

[GasSavers_BEEF]

there is a user here named diamond larry (his car is La Forge and is in the top 10 list) he may have some useful information in his garage. he isn't active anymore but you may be able to send him a PM or something and maybe get in contact with him.

[i-DSi]

Originally Posted by severedgein

Alrighty, the Mrs. and I are finally picking up a Prius, she's got a 50 mile commute to and from work each day. It's about 90% highway (in that dreaded West Palm-Miami section of I-95) and I'd like to get her down to a gallon and a half of gas for that 100miles each day so she's only spending $5 a day on gas (oh what a dream!).

Without spending 3 days searching the forums, what are the best techniques Prius owners have found for reaching that 60mpg range?? Thank you all!

Hi Severedgein,
Just a thought: 'in general' hybrid cars can't deploy their full potential on highways. Reason is simple: the battery can not be used. If it would be used to support, it would be emptied after a few miles.
Result: on highways your Prius behaves just like a normal petrol car. Lucky for you: the Prius is aerodynamically very good.
I drove a couple of times with the Honda Insight (hybrid) and fuel consumption is just a bit better than my 'classic' Honda Civic. But my Civic's cabroom and trunkspace are fare more bigger than the hybrid Insight. Not talking about handling, driving comfort, price (for same equipment)...
So technique for highwaydriving in a Prius is the same as for my car and any other: low and constant speed.
Other trick: an engine block heater. Toyota has them as original accessory.
I'm planning to mount one also. Cold engine starts are a PITA for high mpg.
Good luck with it!

[Fuel Miser]

Originally Posted by i-DSi

on highways your Prius behaves just like a normal petrol car. Lucky for you: the Prius is aerodynamically very good.

Mmm-mmm, wouldn't it be nice if we were offered a hybrid without the hybridization? Just imagine the potential with the weight reduction

[FrugalFloyd]

What they said - slow and steady. A Prius can get 60 mpg at 60 mph for long periods on level ground and slight downhills. If your wife can use slow trucks as blockers and hold speeds down to 55 mph, I bet she can average 60 mpg most days. Massive traffic jams and stop and go traffic probably improve Prius mileage, as the average speed slows, and a heads-up driver goes slow and steady to smooth the speed variation.

[imzjustplayin]

I wonder how much of an advantage an Aluminum Prius would have over the current one. It's annoying to see the old Insight get 70mpg on the highway while the Prius is like in the 50s and its weight isn't even all that important for highway cruising.

[i-DSi]

Originally Posted by *************

I wonder how much of an advantage an Aluminum Prius would have over the current one. It's annoying to see the old Insight get 70mpg on the highway while the Prius is like in the 50s and its weight isn't even all that important for highway cruising.

Hi *************,
Main reasons for the high mileage on highway of the old Insight is
- aerodynamic shape (less drag)
- 3-cylinder engine (efficiency!)
- older emmission regulations (efficiency again) => can run leaner (NOx wasn't that important)
As you already mentioned: weight is not very important for highway mpg.

[theholycow]

Also, wasn't the old Insight a whole lot smaller, therefore having less frontal area (to go along with its better coefficient of drag).

[imzjustplayin]

Well explain to me why the Prius from '01 -'04 -'10 mileage is always around the same for city and highway? The '01 Prius is 42 city 41 hwy, '04 Prius is 48 city 45 hwy, and '10 Prius 51 city 48 hwy...? Why is it so hard for the Prius to achieve good highway mileage? Well I think I know the real reason... it's because of the CVT..

The M/T Insight gets 49 City, 61 hwy for new EPA, 53mpg combined, yet the 2006 Insight CVT gets 45 city, 49 hwy, 47mpg combined... I am indeed aware that the Manual Insight has lean-burn while the CVT either has no Lean-burn or a much less aggressive one henceforth its designation of being SULEV compared to ULEV for the M/T Insight. Despite this fact, the difference in mileage shouldn't be as large as we're seeinig. I read somewhere I think on the Prius Chat forum that because the CVT doesn't lockup on the highway, that it results in poorer mileage. I think this would confirm that the CVT's strength is not highway but city mileage instead and this is somehow holding the Prius back.. Just compare the MPG numbers of the CVT Insight with the Prius and you'll start to see that the city mileage tends to match or exceed the highway mileage by a small amount. I feel I should also note that the Insight is a 2 door vehicle with very good aerodynamics and an aluminum body weighing in at 1800lbs while the Prius has a steel body and weighs a portly 3000lbs, yet the CVT Insight only has an advantage of 1mpg 'combined" over the '04-'09 Prius.

I mean look, if the hybrid system was making the mileage improvement one would and should expect, we should be seeing significantly higher city mileage than highway mileage as technically one should get better mileage in the city since there is little wind resistance. If you compare ALL hybrid vehicles with a CVT transmission, you should start to see a pattern like I have where the city and highway mileage are extremely close. However, I feel the hybrid system should be getting mileage figures more like that of an electric car, like the RAV 4 EV. The RAV4 EV is rated at 125MPG City and 100MPG highway, which actually makes sense. So if a hybrid is using electric motor assist for city driving, then that should mean that these cars should be getting a LOT better city mileage. So I feel it should be an either or, a lot better city or a lot better highway, but not this mishmash of getting the same in the city or on the highway..

However, one should keep this in mind: All the electric cars at this time have 1 speed transmissions with no pump or torque converter to get in the way. Despite the Insight being a hybrid, M/T gets better highway mileage than city mileage, a lot better. In most practices, cars get better highway mileage than city mileage whether they're automatics or manuals. All CVT vehicles seem to have the characteristic of having similar city and highway mileage while A/T and M/T cars have a much greater disparity in city and highway mileage with highway mileage being better...

I'll list a few cars that have CVT transmissions:
2010 Insight: 40 city, 43 Hwy
2005 Civic Hybrid: 39 city, 43 Hwy
2010 Lexus HS 250H 35 city, 34 Hwy
2007 Nissan Altima Hybrid 35 city 33 Hwy
2009 Ford Escape Hybrid 34 city 31 Hwy
2010 Toyota Camry Hybrid 33 city 34 Hwy


But what about lean burn??????? Well for those who are so certain that lean-burn is the end all, be all reason as to why most hybrids suck at good highway mileage, I present the 1992 Honda Civic VX both California AND Federal:
Federal Civic VX: 39 City, 49 Hwy.
California Civic VX: 36 City, 46 Hwy.

So you see, even though the California VX doesn't have lean burn like the Federal VX does, what you see here is an equal drop in city AND highway mileage, not a higher drop in HWY mileage compared to the city mileage.

For those who aren't aware, the '96-'00 & '01-'05 Civic HX with the CVT transmission have Leanburn. That is right, despite the car not using a wide-band O2 sensor like its M/T brother, the Civic HX with the CVT transmission has Lean Burn. For the engine to calculate fuel mixture, it surprisingly enough uses a crank acceleration sensor, something it can't do with the M/T version due to lockup of the engine and the transmission through the process of releasing the clutch.

Here are the fuel economy numbers for the Civic HX '96-'00 & '01-'05 both CVT and M/T.
1996 Civic HX CVT 30cty, 35hwy
1997-2000 Civic HX CVT 29cty, 35hwy
2001-2005 Civic HX CVT 30cty 36hwy
1996 Civic HX M/T, 33cty 41hwy
1997 Civic HX M/T, 31cty 39hwy
1998 Civic HX M/T, 30cty 39hwy
1999 Civic HX M/T, 30cty 38hwy
2000 Civic HX M/T, 30cty 39hwy
2001-2005 Civic HX M/T, 31cty 39hwy

So at first, when you look at the CVT numbers by themselves, it looks like there is a large difference between highway mileage and city mileage, with the highway mileage beating the city mileage. However, when you look at the same car but with a M/T, you start to see that gap extends quite a bit more. So instead of getting 5mpg better on the highway compared to the city, you're getting around 9mpg better.

All of the data I've presented all perfectly meshes together and when you look at it carefully, you can see that it makes sense. The CVT transmission in comparison to a traditional automatic bumped up the HX's city mileage but at the cost of taking down its highway mileage. Had the HX had a hybrid system, you'd probably see the mileage boost from 30mpg in the city to maybe 35mpg or higher.

So to conclude, as many have interated before, a hybrid vehicle's strength is in CITY driving, not highway driving. This is not just because a hybrid uses electric assist in the city but because the CVT transmission itself is what is holding back the hybrid vehicle from getting truly stellar highway mileage. The CVT transmission is an improvement over a traditional automatic if you're doing more city than highway driving and the hybrid drivetrain just sweetens the deal that much more...for CITY driving!

BTW, all EPA numbers in this post are going off of the "new" epa MPG guidelines, not the older ones and I did this to eliminate confusion.

[i-DSi]

Originally Posted by *************

Well explain to me why the Prius from '01 -'04 -'10 mileage is always around the same for city and highway? The '01 Prius is 42 city 41 hwy, '04 Prius is 48 city 45 hwy, and '10 Prius 51 city 48 hwy...? Why is it so hard for the Prius to achieve good highway mileage? Well I think I know the real reason... it's because of the CVT..

I read somewhere I think on the Prius Chat forum that because the CVT doesn't lockup on the highway, that it results in poorer mileage.

Impressive explanation!!
But seriously: what do yo mean with 'a CVT doesn't lock up' ?
A 'classic' AT's locking up is the moment where the torque convertor is 'bypassed' and the cranckshaft is locked with the AT's shaft.
A CVT... doesn't need a lock up I thought because there's no slip in a convertor.
A CVT let's you always drive the lowest possible rpm, also on the highway.
So I don't understand how a CVT can make the difference in mpg. There are clutches in the CVT, but there's no slip once you'e on the move.