2010 Prius Build Thread

[hayden55]

Never noticed a change from gas even if i did decide to pay 20% more for shell 93 E0 boat gas. The car definitely is quicker with all the weight out now. I will eventually make a unique mount for the spare and jack out of the way. With the passenger wiper i noticed its not like Ford's wipers were they sweep outwards, but that it sweeps water to in front of your face and The driver wiper has to work harder.

[ALS]

Being the Prius is designed to run on 87 I wouldn't expect any difference in performance by using a higher octane fuel. It's a waste of money to use any gas with a higher octane than 87. If you could find 87 straight gas that doesn't cost anymore than a nickle higher then it might be worth it. The Prius fuel economy is high enough that E10 doesn't impact the fuel economy like it does on vehicle that gets half the fuel mileage.

[hayden55]

Owning this car definitely makes me rethink the whole cvt hybrid thing. I've never seen a car drop highway mileage so atrociously as a prius driving on a damp road (without rain) and a 10mph head wind, or basically just any condition that isn't superbly optimal. Even in cold weather this car takes a huge hit. I've deemed that even with revised mpg numbers, it's pretty Damn hard to achieve their numbers. You HAVE to basically hypermile to achieve them. Unless your going under 45mph then this car makes a great city car.
70mph, 45F, dry calm weather= 41
70mph, 65, damp road no rain 10mph head wind= 36
I live in AR farm lands so that mileage kinda sucks...
You can view my garage for mods, but what the hell am i doing wrong ?
Looks like i need to swap for a 1.0 ecoboost fiesta instead. 170hp with a tune, 2500lb, and mad autocross skills... Smaller tho����

[ALS]

Have you checked the 12V under the floor in the hatch area? If it is going bad it can cause all kinds of mischief with your fuel mileage.

[Ecky]

It's not that there's anything wrong with the Prius's transmission, it's that with highly efficient vehicles, any losses are relatively much larger. Consider my Insight vs an F150 when turning on the A/C.

Insight - 100mpg @ 50mh
F150 - 20mpg @ 50mph

Convert that to L/100km:

Insight = 2.35L/100km
F150 = 11.75L/100km

Now, let's say running A/C uses about 0.8L/100KM in both vehicles (which is probably close and it's a nice round number).

Insight = 2.35 + 0.8 = 3.15L/100km = 75mpg
F150 = 11.75 + 0.8 = 12.55L/100km = 18.75mpg

So, the F150 loses 1.25mpg running A/C and the Insight loses 25mpg. Ultimately the "loss" and additional fuel cost is the same for both, but proportionally it's much larger in the more efficient car. The same applies to wet roads, headwinds and all sorts of other things that practically disappear into background noise in huge, inefficient vehicles, especially when using a poor metric like miles per gallon.

[LittleBlackDuck]

One other thing to consider is that the Prius is highly optimised for the "average" commute - lower speeds and stop-start traffic. Think about the physics of it.

Highway driving - constant, higher speeds where aerodynamic drag is the dominant force to overcome with energy from fuel.

City driving - lots of stopping and starting, acceleration to replace the energy lost by deceleration is the main use of fuel.

The Prius uses regenerative braking to recover ~60-70% of what would normally be lost as heat in the brakes, and this is where the main savings come from in city driving. How many cars do you know that use less fuel around town vs on the highway?

Also, on the highway the impact of any headwind is exaggerated because aerodynamic drag is proportional to the third power of the speed. At 70 MPH a 10 MPH headwind increases the aerodynamic drag by nearly 50%...

Horses for courses - the Prius excels around town and does damn well on the highway too.

Simon

[hayden55]

Haven't given up completely on the car just because how comfy it is and spacious for the mpgs. Hoping new tires with a lrr stamp could help my numbers a tad.

[oldtamiyaphile]

Originally Posted by LittleBlackDuck

The Prius uses regenerative braking to recover ~60-70% of what would normally be lost as heat in the brakes, and this is where the main savings come from in city driving. How many cars do you know that use less fuel around town vs on the highway?

Prius regen efficiency is more in the 40% range. It's better than friction braking but it's not as good as neutral coasting.

In the hands of a hypermiler, all cars are more efficient in the city than the are highway. The Prius doesn't do that much that you can't do yourself.

[hayden55]

Actually i could see the battery being dead. It looked like an oem Toyota battery. I may call the old car salesman and aee if it has been purchased from them before since it has 3 owners in the same town before me. I haven't had any dash lights, nor have I really monitored battery voltage, but I did notice yesterday definitely after wondering if it used HV battery to power the car when the engine is off and it seemed like it. Went to pick up friends at the airport and with no climate control on, parking lights on only, and listening to my phone on about 15 it went from 60% to 20% HV battery in right at 20 minutes and had to kick the motor on for a little bit to charge before my friends finally got off and got their bags to my car. Looking like $150 for an optima yellow top.

[elhigh]

Any word on that alignment? Your fuel mileage is not fabulous and I wonder how much if could be attributed to the tires fighting each other.

Speaking of tires, check pressure. Fuel economy in the mid-40s on a Prius tells me there is something wrong with yours. Dragging brake pad, leaky injector - something.