Improving Fuel Economy AND Performance together on 2004 Toyota Prius

Add the 25 (actually it's more than that, but the battery cannot deliver more) available HP from the electric motor to approximate available power. also consider that the full torque of the electric motor is available at low speeds so the performance off the line is more than you would expect. Actual 0-60mph is about 10 seconds.

The only time a Prius gets sluggish is if you deplete the battery (as in going up a mountain)

My prius is actually quite tall, but it does have limited ground clearance.

JeffD

 

Its a question of x% increase in performance vs y% increase in fuel burn, the system efficiency can be higher but still result in a net loss. Im not saying thats certain, but you have to consider those cross purposes.

It seems like you are familiar with performance aspects of other engine systems so figure it this way. There isnt that great a difference in output between RS type Impreza and WRX compared to the cost difference, thats why they offer both. Calculate what making the engine breath freer with cleaned up head, valves and exhaust changes, or boosting the intake side while adding aero kit features and wheel tyre combinations will cost what vs financing a later generation 2010 vehicle.

One of your main problems is you cant simply swap the engine out for something with more crank, its too electronically intertwined to the rest of the system. And increasing the electrical potential of the electric drive is out of the question. that leaves the IC engine, batteries, aero, and wheel/tyres.

But if in the end you are determined you should think about aero kit that works rather then air dams full of holes you wont use, look at smooth heavily rounded front spoilers and lower the car, add a diffuser to the rear undertray and sills to the sides. This cuts the amount of dirty air getting under the car and controls how it leaves. The suction side of drag is around 20-40% more important than how a car presents to the air, thats why we pay more attention to the underside and the rear

There arent as yet wheel tyre combinations that Im aware of enough to be convinced will be an improvement, but I would look at larger diameter alloys around 18-19" that arent that much wider (if they exist). Such a combination would have less sidewall give, less rolling resistance, yet the wheel tyre unit could potentially weigh less than more standard series tyres.

The straight out physics of wheel tyre weight suggest it is important for acceleration so you need to be in a position to at least compete with the standard wheel weight offerings. That isnt going to be easy on an empty weight of 2850 lbs.

As some encouragement you have this advantage as time goes by, fuel is never going to get cheaper but batteries are. You dont have to buy into PHEV battery setups right away, but the time will come when there is advantage in doing so.

 

Other than some of the mods to improve handling (Touring suspension and chassis stiffener), the only MPG improvement mod that is there is the engine block heater which helps the warm up cycle in cold weather. I'll avoid saying anything negative about special spark plugs and the "Hyper Force" ignition system.

JeffD

 

A gen2 Prius has an official 750lb load limit. I have had more than that in mine (4 adults plus luggage) and it didn't seem to mind.

JeffD

 

well, that's what your first post reminded me of. sluggish is in the eye of the beholder. take one for a test drive with 4 or 5 people and let us know what you think. you can have two of the following three, power, mpg's and low price. take your pick. prius is mpg's and low price.

 

EPA test

If you want to read about the EPA test (short of reading the EPA's VERY LONG document), see http://priuschat.com/forums/other-c...uth-about-epa-city-highway-mpg-estimates.html.

 

Jimbo is absolutely correct here. (I have a ScanGauge myself.)

The 2nd gen Prius has 110 hp combined.

Someone else mentioned the engine block heater. Yes, that'd likely be a much better investment than most of the questionable stuff you suggested in your first post. You should also consider grille blocking in cold weather. I use pipe insulation which is very cheap. However, you're going to need to remove it as the outside air temp rise so that you don't overheat.

I also agree that getting a 3rd gen Prius likely a better investment than dumping a lot of $ into dubious mods.

 

(I own a 2009, with changes in the computers, other years will vary) If you do grill blocking, the Scangauge allows you to see underhood air tempurature. If it gets above 80F, remove the grill block. It should also tell you when to quit using the EBH. The water temp can tell you when the engine is warm and also can help with when to quit grill blocking and the EBH. I like a tachometer. There are x-gauges, which you can program, to see CAN-Bus values like State of Charge. I watch the nomially 12 volt battery level. (usually 13.7)

 

I bet if you looked long enough, you'd find an off-the-shelf car that suits you to a tee without all kinds of modifications. My Prius is a great car but it makes compromises that may not suit the next guy. Not trying to dampen your enthusiasm - I love enthusiasm. But any car that requires extensive mods to turn it into the car you want just isn't the right car in the first place.

We have a 2007 MX-5 (aka Miata) that is huge fun and drop-dead beautiful. Driven easily, it'll get 33+ mpg. Put your foot into it in the twistys and, although it holds the road like it's on rails, it'll scare the piss out of most people. That may be a better choice for you.

 

This site hints that there is only one public CNG station in all of Georgia. That should influence your decision.
Alternative Fuels and Advanced Vehicles Data Center: Alternative Fueling Station Locator