Hypothetical question - Prius minus the HSD

Which non-PHEV/non-EV at The most fuel-efficient cars and Best & worst cars review, fuel-efficient vehicles got better highway mileage than the Prius?

Here are the results from the 2nd gen: http://web.archive.org/web/20081231...-advice/most-fuelefficient-cars-206/index.htm.

It's unfortunate the CNW junk science still refuses to die , please feel free to use Environmental - Prius Wiki and Lifespan/Operating costs - Prius Wiki as aids. I was tired of always digging thru old Priuschat posts (some my own) for relevant URLs.

Since there's no non-hybrid Prius, a decently close comparison would be highway mileage of the Matrix (since it also has a 1.8L 4 banger). See Best & worst cars review, fuel-efficient vehicles for its results. One can also look there for HyCam vs. regular Camry results. Also look at http://web.archive.org/web/20100820...-fuel-economy/best-and-worst-fuel-economy.htm for older HyCam vs. Camry and NAH vs. Altima results.

Last page of http://www.consumersunion.org/Oct_CR_Fuel_Economy.pdf describes CR's tests vs. the old EPA tests.

One can also consult http://www.fueleconomy.gov/feg/sbs.htm for EPA ratings.

 

I see regen even over 70 MPH, so it is saving me money. Far MORE imortant is that you would never make to TO 70 with out the HSD to add power when accelerating.

The reason you never see atkinson cycle engines without battery packs is acceleration would rival watching grass grow.

(I have owned several cars with less than 70 HP, the Prius is a powerhouse by comparison)

 

i get 55 -60 mpg at 55mph. can a civic or corolla do that? and they are smaller.

 

That sounds like the speed my Geo Metro accelerated to 60 at lol. IIRC, that little 3 banger had a mind blowing 55 HP.

 

Not to mention that the CRX HF had less than 1/2 the horsepower and seats only two. Sigh...

And per Twenty-year-old Civics got 57 miles per gallon - Dec. 19, 2007

 

Can a non-hybrid car achieve better than 48+ mpg at hwy speeds? Yup. I had one over 25+ years ago: 1984 Honda CRX HF. But it only seated two, didn't have NEAR the modern emissions and safety equipment nowrequired by law and marketing, and was even slower than a Prius. From wiki:

the 1.5 liter is rated by the [ame="http://en.wikipedia.org/wiki/United_States_Environmental_Protection_Agency"]U.S. Environmental Protection Agency‎[/ame] (EPA) (under the new rating system) at 41 miles per U.S. gallon (5.7 l/100 km; 49 mpg-imp) city and 50 miles per U.S. gallon (4.7 l/100 km; 60 mpg-imp) highway.[1]

At a constant hwy speed, a traditional ICE automobile can achieve great mpg but that's not real world as we all have to slow down and speed up and the hybrid design can capitalize on that.

 

A non-hybrid Prius operating at highway speeds could get better mileage than the current hybrid version. In fact it would be pretty easy to do so. Unfortunately cars don't get to drive at just highway speeds. This highway optimized Prius would be virtually undrivable at other speeds.

Tom

 

"Any other car" generally means those with Otto cycle gasoline engines. Do any of them match the energy conversion efficiency of the Atkinson cycle engines in Prius and several other hybrids? I don't think so. Only diesels have any chance.

Then there is the transmission gearing issue. I do believe a simple manual transmission could beat the HSD efficiency at any one specific speed and load condition per gear. But "any other car" is going to need something like a 30 speed transmission to adequately match the engine speed to the road speed over the full gamut of operating conditions. The cost, weight, and internal friction of that transmission are going to be serious problems, and few drivers will put up with that much shifting in either a manual or an automatic. And even the available mechanical CVTs can't match the HSD's total effective range of gear ratios.

 

Also, the other guy should go to Power Search and search for 2011-2013 cars powered by gasoline or diesel w/highway mpg >45 mpg. See which ones come up.

 

I drove a 1976 Mazda 808 Mizer station wagon with 59 HP and a 4 speed manual.
Going uphill it could not 'pull' fourth gear, leaving you with a top speed of 37 MPH in third. On the Freeway, with a 70 MPH limit.

My 1978 GLC had the same engine, but a 5 speed manual, much better. Or maybe the 'new' 55 MPH speed limit made it seem better.

Mazda C engine - Wikipedia, the free encyclopedia

 

^^ That 'new' 55 mph limit dated back to 1974. Your 1976 slug shouldn't have seen a 70 mph speed limit sign until it was at least twenty years old.

 

The answer is that, yes, at high speeds a conventional gasoline vehicle could be more efficient, because of gearing and the Prius engine size and use of the atkinson cycle. It would take a diesel to be more efficient at more "normal" high speeds.

But the problem is that then you're sacrificing mileage for all the other times.

Some people just can't handle the truth.

 

Are you envisioning an external slingshot apparatus to accelerate it up to highway speed? :madgrin:

 

He should then come back w/vehicles that get better mileage at 80 mph than a Prius (or ones comparable in size, weight and hp or HSD equipped ones).

You should also point him to http://priuschat.com/forums/other-c...eage-no-its-your-gallonage-really-counts.html and to quote from http://priuschat.com/forums/gen-iii...mileage-gets-worse-in-winter.html#post1411488

Another illustration at http://priuschat.com/forums/gen-ii-...hy-drop-in-fuel-efficiency-6.html#post1378284.

In essence, the people w/inefficient vehicles are the ones (like sub 20 mpg combined full-sized SUVs) who should be caring MOST about getting better mileage via driving habits/techniques, LRR tires, proper tire pressure, etc. Unfortunately, they're least likely to...

 

I tested this theory a few weeks back. While the Prius is undoubtedly super efficient in traffic etc, at about 40-50mph i find it little more efficient than a comparable ICE powered car. I know a country road with a 50mph limit, i often drive on it so i tested the Prius' economy (calculated) and achieved 52.3 over the 10 mile road at a constant 50mph. One thing i find about the Prius is that when the ICE is running, it's not particularly efficient, it seems as if the efficiency comes from being about to cycle the ICE on and off at will. But at 50mph it looses this ability.

I drove the same route in a 1.4 ICE 77hp Fiat Punto, in 5th gear the whole way, changing to 4th for one hill and not revving harder than 4000rpm the whole trip. Both cars with the aircon off. i Achieved a calculated 51.8 mpg figure - barely worse than the Prius.

I've also done this trip in a 180hp lightly tuned 1.4 turbo Fiat Bravo, in 6th most of the way, and got a still decent 46mpg figure from it.

This makes me think that at some speeds a Prius isnt that efficient in comparison to current non-hybrid 4 cylinders (VW's new 1.4 that's capable of 53mpg sounds interesting, as does the 60mpg Fiat Twinair) at certain speeds. That said, you cant beat a Prius in traffic/urban areas unless you go for a Fiesta/Polo eco model which would barely match a Prius in urban driving.