How can I get the highest fuel economy from my 2008 prius with these gas prices?

What references. You mean google me this, google me that?
I'm not sure check your tire ply rating. Youll find out when it happens to you...

 

I would recommend against the K&N filter. I know the general thinking is that the less restriction through the filter the better the fuel mileage. But the thing is that air filter restriction ONLY applies when at full throttle. That's because below full throttle the throttle valve is the greatest meaningful restriction and the air filter restriction has a negligible effect on air flow. So if you drive around mostly at full throttle, ok, get the K&N filter. But if you're trying to get the best fuel mileage, chances are you aren't trying to keep the pedal to the metal everywhere you go.

In my town 85 R+N/2 is considered regular. But I'm also at 7,700 feet above sea level. I don't notice any difference in fuel mileage between regular and our 87 octane "mid-grade".

Keep in mind that oil in the combustion chamber hurts your octane level. If you are burning any oil at all, fixing that problem would help you benefit from lower octane fuel. The best way is to keep your rings freed up, cylinders in good shape and making sure your PCV valve is working properly.

EGR also helps increase octane. So make sure that system is working properly and your EGR cooler is not clogged. Cooling EGR even further helps increase the octane even more, allowing you to use an even lower octane fuel.

If the engine is not burning oil and the EGR system is working properly, one more thing can be done to be able to use a lower octane fuel, is water injection. The problem with water injection is it has the potential of causing more harm than good if not done right. Still, a very well designed water injection system could allow you to use lower octane fuel and get pretty close results to a high octane fuel.

But if pinging isn't a problem it would be actually be better to do the opposite by trying to remove all water out of the EGR system (and intake for that matter). Water and CO2 have a lower specific heat ratio than nitrogen. The lower specific heat ratio causes the combustion gas to make less pressure under the same amount of heat. Of course removing CO2 from the recirculated exhaust gas would be rather impossible, but the water can be removed from it by cooling it even more to the point that the water condensates out of it. As long as you have a sort of catch can to keep the condensated water from getting into the engine, the dryer and cooler EGR not only will increase the total octane but will expand more under the same amount of heat giving you more energy per unit of fuel burnt.

 

The Gen 2 does not have an EGR system, so at least that is one less thing to worry about.

 

In addition to what others have said, for better mpg
-drive slower. Never more than 5 over the speed limit. 5 under would be better
- buy non-ethanol and non-oxygenated fuel. More energy in them. Won't save youoney, but you'll get better mpg.

 

i do. it makes for a bit harsher rides on back roads, potholes, poor pavement, but i think it helps with range and mpg's.
no testing done that i know of though

 

i haven't read of any problems, and many people here do it. there is a recommended max on the sidewall

 

Any idea of the lifespan of these batteries vs stock?

 

Thanks! Shows you what happens when someone tries to sound like a know-it-all!

I haven't looked enough on my Gen 2 that I bought last year to realize it didn't have an EGR system. I simply assumed it did like on my Avalon.

I'd assume, though, that that internal EGR system relies on everything else working properly, so as long as the check engine light is off basically, although that is just a wild guess really.

Preliminary tests seem to put them at least around that of the stock batteries. That being said, I do have my own doubts if you live in the extreme cold as LiFePO4 batteries don't like to be used frozen. But in normal winters there doesn't seem to be a problem.

Still, we won't know for sure until several have used them for +13 years.

But personally, I'm seriously considering them and installing some sort of battery heater since I live in the bitter cold. The street in front of my house is still snow packed.

 

lovely

 

I'm still considering them and so haven't had any experience with them. Others seem to love them and say that they do help get better fuel mileage.

 

I found by avoiding big hills (yep, routing around them) that mileage went up, quite a bit. Stop & go uphill burns fuel, sometimes its charging the pack while going up hill.. Think of the number 45 (mph) it seems to be the number for cruising at good fuel efficiency. Let the car coast more coming to a stop. Let the battery pack move the car from a dead stop. To help with this, get a obd2 reader, torque app, add gauges to a older phone to look at battery HP, GPS speed, ICE RPM, battery SOC, battery termp, get an idea where things are going during accel / decel. Calculate your actual mileage to fuel used. Turns out my MFD is off more than expected, like 34 vs calculated of 45. GPS is within 1mph of speedo. with 235/45x17's..

A BIG concern i had was oil consumption... I thought the engine was going south...On downhill, the battery pack was filling up before i got to the end. What i saw was when the pack is full, engine shuts off for ~ 15 more seconds (during downhill regen) and it starts back up! For the next mile downhill the engine is revving 2-3krpm. Now, when i see engine shut off during downhill regen on the torque app, i put it into neutral for the rest of the hill, and my oil use now is 2qts/ change vs 1qt/tank. Huge difference. When its hot outside, I try to stretch out my braking distance to soften energy going back into the pack. Real hot out (>105F) I use AC and blow it towards the battery inlet (not recirculating).
The app was the biggest help to figure this out. Hope that helps, 198k 06

 

The 1960s just called and want their MMO back.
A quick question, at what point does one use MMO?