Why isn't gas mileage improving for new vehicles?

[besserheimerphat]

Idiotic CAFE standards by politicians forced automakers to ditch 6-cylinders (in the name of 'MPG) and stick turbos on 4 cylinders--- which are installed in sedans and mid-size SUV's.

Turbos creates boost but turbos can disintegrate after 7-10 years and cause carbon build-up, blow the engine, etc.. The 4-cylinders are OVERWORKED

Nobody mandated that automakers put turbo 4s in place of 6 cylinders. That was the automaker's choice. Most autos are designed for a 10ish year life. After that you should expect to replace some major components. That's just a fact, and something you should factor in when paying all cash for that 12 year old car vs making payments on a 2 year old car. Nobody is designing a car to last a half million miles because no one could afford it. No one ever has. The issue is they didn't have the engineering tools and manufacturing precision we do today, so they just added more material without knowing how over built they were. Not to mention, "those old cars" were rarely as reliable as people remember they were. Automakers design cars to have 95%+ chance to last through the second owner.

 

[ArgentCy]

And to top it off diesel fuel is burned in a Diesel engine which is much more efficient at converting that fuel to energy than the otto engine used to convert gasoline to energy (energy meaning mechanical as opposed to heat)

As well as the temperature. The larger the temperature difference between the engine and the surrounding the higher the theoretical efficiency.

 

[ArgentCy]

Nobody mandated that automakers put turbo 4s in place of 6 cylinders. That was the automaker's choice. Most autos are designed for a 10ish year life. After that you should expect to replace some major components. That's just a fact, and something you should factor in when paying all cash for that 12 year old car vs making payments on a 2 year old car. Nobody is designing a car to last a half million miles because no one could afford it. No one ever has. The issue is they didn't have the engineering tools and manufacturing precision we do today, so they just added more material without knowing how over built they were. Not to mention, "those old cars" were rarely as reliable as people remember they were. Automakers design cars to have 95%+ chance to last through the second owner.

Someone tell Subaru to beef up the wheel barings though. Always been a problem for them and I just had to replace a really bad one at 110k miles.

 

[dafarmer]

Someone tell Subaru to beef up the wheel barings though. Always been a problem for them and I just had to replace a really bad one at 110k miles.

Our Subaru has "bearings", as anyone who knows anything would know.

 

[flycy]

In Europe, most cars are run on diesel fuel. And the vehicles far more fuel efficient. In Ireland, I rented a luxury wagon that got over 40mpg. Diesel is less expensive than gas there. Fuel prices in Ireland were around the $6/gal mark when I was there.

They don't have the same emissions requirements in Europe thus better mpgs.

 

[motorcy90]

Gotta Hemi...what was the question again?

The gf and I call them penismobiles

yep to me anything above a small lift 2-4" on a truck is nothing more then bragging I got a small member. the 4" allows for some more aggressive tires to be run but still keeps the truck somewhat usable.

 

[Die4Cy]

Most of the kinks in the diesel emissions systems have been worked out. Things like EGR are much more reliable now. And there's a hell of a difference between a bad EGR valve and a "bad engine."

A diesel will always out pull a gas truck. So if you need to move big loads, diesel is your best bet. It's a hell of a lot cheaper to rent a big truck for a day than it is to buy, operate and maintain a 3/4 or 1 gas truck when you only really need it 10 days a year.

I trailer 20-50 miles almost weekly with a 3/4 ton up to 15,000 pounds, and could never make a diesel pencil out. Still pull with a 14 year old truck with a 6 speed manual because it is reliable and the mileage cost is low even at 8-10 mpg. See a lot of those diesels out there though, to each their own.

My personal pickup is an Ecoboost F150 and I'm very impressed with the amount of power and torque a little 3.5L engine can make with all the engineering modern vehicles put on the pavement.

My first car was a 1983 Oldsmobile Cutlass Supreme with a 3.8L V6 (15 mpg max) in a vehicle that weighed 40% less than my truck and had less than a third of the horsepower from roughly the same displacement (110 vs. 360). There is a reason it was known as my "Gutless Cutlass."

In 30 years, we've figured how to take an engine that size, triple the horsepower, double the torque, put it in a vehicle that weighs 3000 pounds heavier, and still get 33% better fuel economy.

The progress that has been made is significant.

 

[SpokaneCY]

Guys buzz by me all of the time (I've looked ahead and see the light turning red) and than have to brake hard and a few seconds later I am in the lane right next to them again and we are all stopped at the same light. It's not the Tour de France where you get bonus points off your time by reaching certain points first. Smooth is the name of the game in braking, acceleration and shifting.

A penny saved is a penny earned, right grandpa?

 

[SpokaneCY]

The gf and I call them penismobiles

What kind of vaginamobile do you drive?

 

[SpokaneCY]

Idiotic CAFE standards by politicians forced automakers to ditch 6-cylinders (in the name of 'MPG) and stick turbos on 4 cylinders--- which are installed in sedans and mid-size SUV's.

Turbos creates boost but turbos can disintegrate after 7-10 years and cause carbon build-up, blow the engine, etc.. The 4-cylinders are OVERWORKED

Continuous Variable Transmissions (CVT) , now coupled w/turbos found on Hondas causing all sorts of problems,

CVT's can't go on trucks---worthless....

We rented a Nissan Rogue (wCVT) non-turbo for mountains in N Arizona last March. Biggest piece of CRAP ever. Overworked crappy 4-cylinder.....sounded like a lawn mower, struggling n higher altitudes

I like my 2017 CRV. I miss my 2007 range rover sport. My johnson is average.

 

[motorcy90]

Most of the kinks in the diesel emissions systems have been worked out. Things like EGR are much more reliable now. And there's a hell of a difference between a bad EGR valve and a "bad engine."

A diesel will always out pull a gas truck. So if you need to move big loads, diesel is your best bet. It's a hell of a lot cheaper to rent a big truck for a day than it is to buy, operate and maintain a 3/4 or 1 gas truck when you only really need it 10 days a year.

Most heavy duty manufacturers are still fighting EGR issues and over all reliability from that. one of my co workers used to be the service manager for one of the big construction/farm companies big dealer here in eastern IA more then half of their service/warranty work was emissions related. even in trucking your seeing increased costs and maintenance from all the emissions requirements, so much that glider trucks are so popular from it.

 

[SpokaneCY]

I don't know if I'd call it bad ethics but it does look trashy and doesn't help with the stereotype of hunters being tabacker chewin' , beer drinkin' , uneducated rednecks. I like to think people like Steven Rinella, Cam Hanes, and Bill Winke are a more accurate representation of hunters than Bubba from the trailer park carrying a Mt. Dew bottle for a spitter everywhere he goes. Unfortunately I've been to the Iowa Deer Classic enough to know there are plenty of Bubbas in our community.

World needs both yuppies and bubbas...

 

[BigBake]

I trailer 20-50 miles almost weekly with a 3/4 ton up to 15,000 pounds, and could never make a diesel pencil out. Still pull with a 14 year old truck with a 6 speed manual because it is reliable and the mileage cost is low even at 8-10 mpg. See a lot of those diesels out there though.

My personal pickup is an Ecoboost F150 and I'm very impressed with the amount of power and torque a little 3.5L engine can make with all the engineering modern vehicles put on the pavement.

My first car was a 1983 Oldsmobile Cutlass Supreme with a 3.8L V6 (15 mpg) in a vehicle that weighed 40% less than my truck and had less than a third of the horsepower from roughly the same displacement (110 vs. 360). There is a reason it was known as my "Gutless Cutlass."

In 30 years, we've figured how to take an engine that size, triple the horsepower, double the torque, put it in a vehicle that weighs 3000 pounds heavier, and still get 33% better fuel economy.

The progress that has been made is significant.

I was going to strongly disagree with the OP, your post summed up my feelings perfectly.

Owner of a 2012 F150 Ecoboost, It is leaps and bounds more fuel efficient than my father's 1981 Chevy that he used for farming. On top of that the newest model went all aluminum and I'm sure still gets better mpg than my 2012.

 

[IcSyU]

I was going to strongly disagree with the OP, your post summed up my feelings perfectly.

Owner of a 2012 F150 Ecoboost, It is leaps and bounds more fuel efficient than my father's 1981 Chevy that he used for farming. On top of that the newest model went all aluminum and I'm sure still gets better mpg than my 2012.

I had a 2014 with Ecoboost and have a 2017 with it now...mileage is probably 10-15% better.

 

[BoxsterCy]

A penny saved is a penny earned, right grandpa?

Nope. I am known by my friends for spending too much on about everything. It's about being smooth. Smooth is cool. Not saying I don't run the Porsche through the gears because I do and it sounds cool as **** when I do, I just do it smoothly.

 

[rudiskilz]

I know there are examples of new vehicles that are getting 50+ but most American made are still stuck below 30. Trucks as low as 15 mpg! (2019 Ford F150s)

American made vehicles are being left in the dust. Why are we so rapidly advancing in technology in so many areas but fuel technology isn't improving?

We bought a 2018 Honda Clarity Plug-in Hybrid (same size as an accord) when my wife started to work in home health field. In the summer time it gets 50 miles on a full charge...... Most of the charging stations around town are free as well. Pretty sure we haven't gotten any gas for nearly 2 months now. and the 7500 tax credit was a nice bonus come tax season as well...

 

[usedcarguy]

Two things to add. E85 even with half the BTUs is capable of far better mileage. However, it would require a much higher compression engine to take advantage of it's properties which would make it incompatible with gasoline. They're working on variable compression engines. If they ever figure it out, it would be a game changer.

The other is that variable cylinder technology, turbos, and other things which have added marginal efficiency to economy thus far have been sadly unreliable. Things which were almost a thing of the past such as oil consumption are now commonplace again. Any money that has been saved in fuel economy has been wasted in long term repair costs. And I would argue wasted at an exponential level.

Oh, and one more thing. Honda's are designed for a 20 year/200k lifecycle. I would assume most cars today are. But this extra crap on them is not helping reliability one bit.

 

[besserheimerphat]

Most heavy duty manufacturers are still fighting EGR issues and over all reliability from that. one of my co workers used to be the service manager for one of the big construction/farm companies big dealer here in eastern IA more then half of their service/warranty work was emissions related. even in trucking your seeing increased costs and maintenance from all the emissions requirements, so much that glider trucks are so popular from it.

There's a whole host of parts and potential failure mechanisms for EGR systems. I'd be curious to know what make and year your coworker was experienced with. I know we had some issues as recently as 2013, but our stuff has been pretty solid since then as far as I know. I'm a reliability engineer for PACCAR, parent company of Kenworth and Peterbilt. I focus more on trucks in development than current product, but I still hear about the big issues with our powertrain (not with the Cummins gear though).

Part of the reason emissions components get the brunt of the anguish is because we are forced to turn on a dash light when a malfunction is detected even if it has no effect on the drivability of the vehicle. If the offset on a NOx sensor is too high, dashlamp. If the SCR efficiency is too low, dashlamp. Even the ambient air temp sensor is part of the emissions equipment because it is used to control fueling, and a bad sensor can lead to excess soot or NOx production. Meanwhile, the driver doesn't notice any symptoms other than a dashlamp.

Yes it does increase costs. We have to answer not just to the operators but also to the regulatory agencies. Sometimes those two "customers" have competing requirements. If we don't meet most of the operators demands we sell fewer trucks. If we don't all of the agencies demands we sell 0 trucks because they won't certify our vehicles. And they are coming after gliders too. We tried to price them so high no one would buy them. Not sure how many we still sell, if any.

 

[2speedy1]

As far as Trains go, that is a completely different subject. Very little can be compared.

First, there is few emissions standards compared to what is on vehicles. One diesel, 16 cylinder Locomotive today runs about 4500 hp, and has around 200,000 lbf. of tractive effort. With most trains running 3 to 6 Unit consists, depending on the length and weight of the train.

Second, you have to realize how Diesel electric locomotives work. The diesel engine turns a generator that powers electric traction motors on each axle, putting tractive effort to the ground. They use Dynamic braking as well as air brakes. It is basically a Hybrid vehicle, but has no battery storage capacity, only a diesel generator producing the electric power (diesel over electric hybrid.)

Third, momentum is a big factor, once you get 20,000+ ton moving it tends to stay moving. Steel wheels, rolling momentum, inertia, etc. all in play here. Physics majors on here know more about this.

Fourth, its not about MPG. Its about Ton Miles Per Gallon, Railroads are averaging about 480+ But when one rail car is about 4 times that of a semi load and trains average about 150 cars per train, making it hard to compete.

 

[simply1]

Just curious if this would attract anyone.

Likely based on the next-generation F-150 (due before the middle of the next decade), the battery-electric model is sure to offer impressive performance and driving range from the get-go. Expect the F-150 Electric to come to market with a towing capacity of at least 10,000 pounds and a driving range of more than 200 miles.