'16 real MPG

I just read Motor Trend's review of the '16 Prius. According to their Chevron sponsored "Real MPG," the Gen 4 Prius Four Touring (Li-ion battery pack) is good for ~56mpg overall. (Note this was a non-Eco '16 Prius which is EPA-rated at 54/50mpg cty/hwy)

2016 Toyota Prius Four Touring First Test Review

Out of curiosity, I wanted to see what the "Real MPG" was for the Gen 3 Prius... but the only model Motor Trend provides "Real MPG" test numbers for is the Prius C. What gives?

Since the Gen 3 is EPA-rating is at 51/48mpg- I'm curious how the "Real MPG" numbers compare.

Anyone care to provide an estimate (based on overall experience) for what Motor Trend's Gen 3 Prius' "Real MPG" numbers might be?

My '11 Gen 3 has returned +49mpg (without trying) for 44k DD miles. I have gotten +56mpg tanks at times with some hyper-miling tricks, but not without pissing other drivers off (easy to do in & around DC).

I'm curious to see how much better a Gen 4 Li-Ion could potentially be compared to my Gen 3.

Thanks in advance.

 

O.K- did some digging with Motor Trend's Real MPG. Their online vehicle selector actually does provide the numbers for a 2014 Gen 3 Prius- they just wrongly picture a Prius C on the screen. The moderators are in the process of fixing the image mix-up.

According to MT's "Real MPG" the Gen 3 is rated at 54.7mpg / 47.9mpg cty/hwy
Compared to the '16 Gen 4 (Li-ion, non eco) Prius: 56.4mpg / 56.2mpg cty/hwy

So, the Gen 4 provides roughly 3.1% better city mileage
but a whopping 17.3% jump in the highway. That 1.5% improvement in ICE thermal efficiency, plus the lower Cd, lower mech friction tranny, & low RR tires really make an impact at highway speeds!

For giggles, I compared this to the Fuelly numbers:
Prius C weighted average is 47.9mpg
Gen 3 Prius weighted average is 47.46mpg

So, based MT's numbers & my guesstimates, the (Li-ion, non eco) Gen 4 should eventually avg right about +/~50mpg from the Fuelly crowd.
Sure, YMMV, but this is a good baseline for comparison.

Finally, based on everything I have read about the Gen 4, I'm not sure the Gen 4 Eco buyers will see much better mileage results than MT's estimates. In fact, I strongly suspect Toyota may end up having to revise their Eco estimates down to more closely match the rest of their Li-ion line-up... Simple physics suggests that there aren't enough vehicular improvements (lower RR tires @ higher inflation pressures, slightly lower weight, windshield coating?) to yield the Eco's higher mileage estimates (58/53mpg) when compared to the other Li-ion Prius models (54/50mpg).

 

Folks, YMMV. So, take all the reviews, conjecture, & guesstimates made from said reviews with a grain of salt. MT has gone through great lengths & a corporate sponsorship to create their "Real MPG" numbers for every vehicle on the road, simply because many feel the EPA numbers are simply not accurate. But even MT's "Real MPG" numbers as well as Consumer Reports test numbers should be taken with a grain of salt... YMMV

Based on the improvements Toyota has reported on their Gen 4 I am comfortable with the roughly 3.1% better city mileage MT's returned.
However, I am highly skeptical about MT's whopping 17.3% MPG jump on the highway.

Physics:
A small 1.5% improvement in ICE thermal efficiency, an ever-so-slightly reported lower Cd, pumped-up lower RR tires, & a special windshield coating are insufficient to make that much of an impact at highway speeds.
While RR & mech friction are ever-present, & improvements to these two would easily explain the 3.1% increase in city mileage, overcoming aero drag becomes the largest power requirement at highway speeds; power requirement increases with with the cube of velocity.

Gen 4 aero drag was marginally reduced based on a smaller frontal area & claimed Cd reduction of .01. Cd*A for the Gen 4 is 6.28ft^2 vs. 6.58ft^2 for the Gen 3. A 4.56% reduction in CdA is commendable, yet not enough to make such a large MPG improvement at highway speeds. There has to be more. Could it be Toyota's reported lower friction tranny? Could it be the MT guys got lucky?

Either way, seeing MT was able to get such good mileage with a non-eco Prius, I stand by my suggestion that Toyota will probably have to revise their Eco model MPG estimates from 58/53 mpg down to more closely match the rest of their Li-ion line-up models' 54/50mpg.

Of course, there will be folks like Wayne who will blow all the EPA estimates out of the water. But, as previously stated, I think the average Fuelly contributor will most likely avg ~50mpg overall- which is a big improvement over what Fuelly drivers report for the current Gen 3 (47.5mpg) & the Prius C (49.4mpg) on Fuelly.

Bottom line, I am very pleased with the first set of fuel economy numbers on the Gen 4. I look forward to trying to beat my own personal Gen 3 mileage records with my own Gen 4 someday. YMMV- but have fun!