58 MPG by 2032

[Grumpycat]

Let’s clear one thing up, the slower you go the better mpg you get. I don’t have cold hard facts but most vehicles will probably get the best fuel mileage at about 45 to 50 mph. It’s just physics.

Yup, but there is at least one unicorn out there. A 2000 Toyota Avalon with OE 16" wheels maxes MPG around 67 MPH. I drove about (20) 500 mile days in mine to know. It was the damndest thing but 28 MPG at 60 MPH and 30-34 at 70 MPH. Back down to 28 at 75. Miles on odometer divided by gallons purchased at the pump. Yes, on a day with low traffic I held to 60 MPH for 500 miles, I was that curious.

Mentioned on Avalon forums and got a lot of "everybody knows that is impossible!" but several, "me toos, I thought I was going insane."

This car was geared very high. Apparently it grunted at 60 MPH at too low of an RPM for efficiency so much so that the engine efficiency increased faster than wind resistance up to about 67-68 MPH.

The problem is that ICE specific-power efficiency is not linear. If you need 30 HP from a 200 HP engine there is one RPM which uses the least fuel for that HP. There are many RPMs which can produce that HP.

With this same car a bare empty cheap less than 200 pound trailer with nothing but a 4x8 sheet for a bed knocked MPG down to under 20 no matter what speed. Add a motorcycle to the trailer, no change.

The 2nd generation 2004-2009 NHW20 Prius will max MPG at 41 MPH.

 

[oosik]

58 mpg. They will have to put outside "push bars" on vehicles for the passengers to push on.

 

[Oaktree]

I agree with the initial point, but it wasn't the industry, but the media and politics that led to high barriers to entry that allowed Europe and Asia to vastly outpace the US in nuclear energy production.

I stand by my comments on the industry's arrogance. Back in the mid-70s (pre-3 Mile Island) when PSNH was looking to put the Seabrook plant in here in N.H. we'd hear constant hype of "electricity too cheap to meter", and a general disregard for any sort of environmental protection (they were just planning on using ocean water for cooling). None too forthcoming on any sort of evacuation planning either...N.H.'s rather small seacoast is very crowded in the summer).

Their parent company doesn't seem to have learned their lesson, given their continued arrogance with the Northern Pass power line that was proposed a decade or so ago.

 

[Oaktree]

Yup, but there is at least one unicorn out there. A 2000 Toyota Avalon with OE 16" wheels maxes MPG around 67 MPH. I drove about (20) 500 mile days in mine to know. It was the damndest thing but 28 MPG at 60 MPH and 30-34 at 70 MPH. Back down to 28 at 75. Miles on odometer divided by gallons purchased at the pump. Yes, on a day with low traffic I held to 60 MPH for 500 miles, I was that curious.

To say I'm skeptical would be the understatement of the year. Even for toyota fanboys' propensity to exaggerate fuel mileage or durability this takes the cake.

 

[WinterDeere]

A 2000 Toyota Avalon with OE 16" wheels maxes MPG around 67 MPH. I drove about (20) 500 mile days in mine to know. It was the damndest thing but 28 MPG at 60 MPH and 30-34 at 70 MPH. Back down to 28 at 75. Miles on odometer divided by gallons purchased at the pump.

I believe it. But here we're talking about achieved MPG rather than maximum possible MPG. Maximum possible will always follow speed, as the physics showed, but achieved may indeed be a bell curve due to secondary factors (gearing, engine efficiency vs. given RPM, etc.). It's likely that a different gear selection, whether by operator or manufacturer, would push that curve around a good bit.

 

[NoTrespassing]

I believe it. But here we're talking about achieved MPG rather than maximum possible MPG. Maximum possible will always follow speed, as the physics showed, but achieved may indeed be a bell curve due to secondary factors (gearing, engine efficiency vs. given RPM, etc.). It's likely that a different gear selection, whether by operator or manufacturer, would push that curve around a good bit.

True, I might be able to gain 1 or 2 mpg by dropping from 6th to 5th gear and driving say 35 mph instead of 45 mph in 6th.

 

[Grumpycat]

I stand by my comments on the industry's arrogance. Back in the mid-70s (pre-3 Mile Island) when PSNH was looking to put the Seabrook plant in here in N.H. we'd hear constant hype of "electricity too cheap to meter", and a general disregard for any sort of environmental protection (they were just planning on using ocean water for cooling). None too forthcoming on any sort of evacuation planning either...N.H.'s rather small seacoast is very crowded in the summer).

Nothing wrong with using ocean water. A reactor in Florida had similar problems with environmentalists and local fishermen. Was forced to build a long canal for their spent cooling water to further cool off before reaching the ocean. After a few years their output pipes were clogged with lobsters who loved the warm water. Paid fishermen to clean them out the first year. Next year the fishermen returned expecting easy free lobster but the utility said, "not on our property." Lawsuits followed. Utility won. Fishermen could have had a free source of plentiful lobster but they let supposedly expert marine biologists claim lobsters would be harmed by warm water forcing the utility to build the canals.

In other news, crocodiles like nuclear plant "cooling" canals. What they don't mention is other life must like the canals else the crocodiles would have nothing to eat. A Nuclear Plant's Cooling Canals Help Save Endangered Florida Crocodiles

 

[Grumpycat]

I believe it. But here we're talking about achieved MPG rather than maximum possible MPG. Maximum possible will always follow speed, as the physics showed, but achieved may indeed be a bell curve due to secondary factors (gearing, engine efficiency vs. given RPM, etc.). It's likely that a different gear selection, whether by operator or manufacturer, would push that curve around a good bit.

It is an intersection of 3D curves, drag vs velocity, engine specific-output efficiency vs RPM, and engine HP output vs RPM.

Velocity is the governing variable for wind drag.
Then at that drag we know what HP is needed.
At that HP we need to find the optimal RPM for efficiency.
Perhaps a CVT can deliver that optimal RPM? My Subaru sure seems to try.

Maximum achieved in the Avalon was found at 67 MPH. Physics theories be damned, this is engineering.

 

[ultrarunner]

The best mpg cars I have driven were small VW diesels rented in Germany…

I was impressed and enjoyed the stick shift and plenty of grunt for mountain passes.

I looked into to getting here just about the time of the VW Diesel emission scandal…

My 1938 Bantam 60 advertised top speed of 60 and top mpg at 60 albeit at a much slower mpg test.

Best modern gasser would be Moms 2001 Toyota Corolla… some tanks hit 42 mpg… even higher from Lake Tahoe to the SF Bay Area (Downhill)

Spent the day watching mom’s Corolla being built as guests of the President of Toyota… even sitting in the car going down the line as the assembly teamed signed the engine compartment…

 

[Fixastuff]

@Grumpycat

It is an intersection of 3D curves, drag vs velocity, engine specific-output efficiency vs RPM, and engine HP output vs RPM.

Velocity is the governing variable for wind drag.
Then at that drag we know what HP is needed.
At that HP we need to find the optimal RPM for efficiency.
Perhaps a CVT can deliver that optimal RPM? My Subaru sure seems to try.

Maximum achieved in the Avalon was found at 67 MPH. Physics theories be damned, this is engineering.

If you dropped it down a gear and went slower at the same rpms you would probably get higher MPG.