Prius Eco 58 MPG vs Prius 54 MPG - What's the difference?

If you have been reading -all- the Toyota supplied info. (good luck with that! - there is so much now), -Toyota- will be offering a kit to cover the white plastic interior parts. So that becomes a non-issue, though -I- still like the white! So there!

I am certain that the mileage figures given are EPA measurement method results, probably currently sitting in the EPA "in basket", waiting for adoption. The manufacturerers are still required to do the measurements and submit them. Always subject to further testing by an EPA contractor, of course.
Now, while lately (last 3-5 years) the EPA numbers are very close to what many get, with just a little work most can best those numbers, some by a lot!
There has been speculation that the G4 may offer a lot of opportunities to do so (better the EPA numbers). Certainly in colder areas it appears to have advantages over the G3.

I submit to you my opinion that the mileage improvement of the "model 2 ECO" is due to the measurement methods. Whether it appears in the "real world" remains to be seen.

As for the special tyres purportedly used, -I- prefer tyres that work as tyres, that is, give good traction, don't fail after "minor" incidents, and don't require "white glove" treatment. The best work well in all weather environments, tyres such as the Nokian WRG3. Just in case you might think my wants are impossible.

 

Ok, valve opening/closing varies, that's different.

Variable lift valves is something the Civic Hybrid used, worked well. The usual lift was sufficient 90% of the time, improved mpg, but if you had a heavy load the higher lift cams were shifted over, and you got a momentary boost.

 

What color?

White Duct tape! ?

 

If reduced weight can't fully account for the eco's improved MPG:

• Could it sit slightly lower
• Tweaked engine software
• Tweaked cam
• Different tires
• Is it missing a mirror
• Better binned inverter parts?

 

Just dragging out stuff from my Civic Hybrid experience, yup: tweaked cam is a possibility, and maybe dual spark plugs per cylinder?

 

No you can't, because there are numerous occasions where you want sub 10 kW of power from the ICE, even at 1,000 rpm at WOT in 1.8 engine there would be too much power.

 

I'm thinking that the Prius Eco's CVT works in some permanent Eco mode, as you could do by pushing the Eco mode on the regular Prius. I think the weight reduction only accounts for a small part of the fuel-economy gain, the rest coming from the CVT permanently running in some Eco mode.

 

ECO mode pretty much does squat.

 

Maybe the Eco model's Eco Mode is different.
Maybe Eco Mode for all Gen 4's is different
Maybe the Eco model's default start-up is in Eco mode so the EPA testing for it is done in Eco mode with the other models tested in Normal mode, their normal start-up mode.
OTOH, maybe not. At this stage its speculation.

 

IIRC, Toyota's said all the modes have been shifted, in the direction that the 3rd gen pedal Normal response will roughly equate to ECO in 4th gen.

 

maybe they filled the chassis with hydrogen.

 

And the super LRR tires, but the rubber can't contain the H2 very well and so need to be refilled every time you refill the main tank every several days....

 

bisco and Jeff N:
They'll stay that way until the Hindenprius disaster, which will cause everyone to change to helium.

 

US Prius 2016 just went online at toyota.com today. So, it's not the weight. It's not the battery. It's not the tires. The only variable that is left is a different CVT programming for the Eco.

 

why is it not the tyres, high performance windscreen and rear wiper?

 

Same-size tires. LRR or not makes almost no difference. Weight difference is only 40 pounds between Prius Eco and Prius 3 or 4.