Follow us today...
One of our readers posted a great comment under a story recently asking why there are no diesel hybrid cars in the US market. At first blush it seems like a no brainier. Both appear to offer great fuel efficiency. Why not marry the two? Maybe appearances are deceiving and there are some sound reasons against the technology, or maybe it is just convention. Let's break it down.
First, we should review the goals of cars like the Prius and Honda Accord hybrid. Obviously achieving the most miles per gallon practical is the first goal. Next many would list environmental friendliness. This goal has a few aspects, but emissions at the most measurable and most noted environmental metric, with CO2 emissions in particular being important. Fuel economy is certainly a goal. This is related to fuel efficiency and MPG, but takes into account the cost of the fuel. This might seem obvious, but lowering the amount of crude oil used to make the car go is an objective of many hybrid buyers. Finally, overall cost of ownership needs to be considered. You might notice we have left off drivability. Yes, everyone wants a car that can accelerate safely, but a quarter million people per year buy a new Prius or one of its copycat makes, and they all are relatively slow and handle a little sloppily. We can include this as a goal, but let's not delude ourselves. Most affordable hybrid buyers put that low on their list of needs and wants as proven by current and past sales.
Now let's get the hard facts out of the way. There is no affordable diesel car in the US market that is the fuel efficiency leader (MPG combined) in its class. We have done that story before so if you need to look back do so now. Gasoline cars are the liquid fuel champs in the US in terms of combined fuel efficiency. So starting with a diesel has that disadvantage already.
The next goal is emissions. We want them to be as low as practical. Here again gasoline cars are beating diesel cars. Until very recently diesel cars were much more polluting by pretty much every measure. Then government stepped in to stop that. Diesels now are not allowed to produce the fine particulate and oxides of nitrogen they used to and need to be in line itch gasoline cars. However, the diesels still produce more CO2 per mile than gasoline cars. So in terms of measurable environmental impact, gasoline cars are again the starting place.
Fuel economy is next. Here in the US diesel costs about 20% more than gasoline. Taxes are only a small part of the reason why. Things could be done about that which might help with this, but in the US we presently use all the diesel fuel that we produce domestically. Sure, we could artificially lower the price of diesel in comparison to gasoline like many European countries do, but why? The fact is that just to match the fuel economy of a gasoline car like the Corolla, which can get 35 MPG combined, a diesel rival needs to achieve 42 MPG.
Related to this issue is that diesel in America is currently much worse than gasoline in terms of miles per gallon of crude. That is because l like it or not, the US refineries create much more gasoline from a gallon of crude than diesel. The EIA says it is 11 gallons of diesel and 19 gallons of gasoline per barrel. Since we are already a net importer of liquid crude, why import more just to switch to diesel?
Diesel vehicles offered by automakers that also have a similarly powered gasoline engine option charge more for the diesel. It seems the diesel engines cost more to make. So the initial cost is higher. Could that be offset by lower maintenance costs, or higher residual value? Maybe.
Finally, we come to drivability. Diesel lovers always cite two things about the cars they like most. First, the relatively higher torque compared to naturally aspirated gasoline cars. To me that is a non-issue. All diesels now use turbos, and the torque is nice, but turbocharged gasoline cars are also torquey. The electric motor drive from the hybrid is also going to add torque to the vehicle, so the diesel advantage here is not very helpful. Plus, there are turbocharged gasoline hybrids on the market now so that is clearly a possibility.
Next the diesel advocates cite the great highway fuel economy of diesels. This is a valid advantage of diesels. Remember though, the hybrid we create is going to have all the aerodynamic and rolling resistance improvements possible. Is slightly better highway mileage worth the compromises we have already listed out that diesels force us to live with?
After a closer look the diesel hybrid makes less sense. If you need any proof that automakers that have in the past pushed diesel are now turning to gasoline electric hybrids look no further than Volkswagen. Their new Golf GTE hybrid will soon join the Jetta (turbo gasoline) hybrid in the US market.
Related Stories:
Why a compressed natural gas plug-in electric hybrid makes sense
Diesel vehicles blamed for polluting Paris air by authorities
Follow us today...
Comments
I agree totally Bio-Diesel
Permalink
In reply to Sad that you skirted the key by edward Hujsak (not verified)
I agree totally Bio-Diesel Electric is the future. Diesel engines can run on both bio diesel and conventional diesel if you ad a hybrid to the mix and you are pushing the mileage to unthought-of potentials. Plus, a diesel engine will last 2 to 3 times that a gasoline engine will last. When I was in the Navy we were resurfacing’s some range roads on 29 palms Marine Corp base in California all of our equipment runs on Diesel the base had converted to bio diesel so we just filled the trucks and equipment with the bio diesel and they ran great. The point is there is no special modifications to the engine, you will have to change out the filters. But that is because bio diesel cleans out all the crap from conventional diesel. I think the problem is that Americans don’t know much about diesels they only know the big rigs on the highways.
My VW Jetta TDI has a clean
Permalink
My VW Jetta TDI has a clean exhaust. It performs well, pulls a trailer and gets 40 mpg average city and highway (without the trailer). Imagine what that engine would do if combined with hybrid technology. Remember the Audi diesel hybrid that won at LeMans? I'd love to see diesel hybrids offered in the U.S., but I fear political interests will keep it away.
Hi guys. I love these topics!
Permalink
Hi guys. I love these topics!
Let me give some hands on objective data for you.
I will start off by saying that gasoline engines are not and never will be the combined fuel economy leaders. I find it funny when folks go off of spa ratings to make their arguments. There are a number of things wrong with this.
First: EPA ratings are still done at 55 or 60 mph for highway usage. Take a gasser up to 80 and watch that great mileage number drop like a stone.
Next: epa testing does diesel no favors. This is proven.
My personal test cycle:
I drive 220miles round trip daily to work. 75% of which is highway miles. I keep my cruise set for 53 mph in the back roads and drive conservatively on local streets. My cruise gets set to 68 on the highway.
The test cars:
'14 Passat TDI se manual (my car). 55k miles
'14 passat se auto. 5cyl gas. 15k miles
'15 Passat tai se auto. 4cyl turbo. 8k.
Now, my whole goal with the two gas loaners I had was to try to get as close to the TDI mileage that I could, so I was really conscientious of my driving them. I had a week in each car BTW
The results:
TDI - 56mpg with ease. On rare instances I have gotten over 60. Nice! I can do 80-85 and still get over 45. 75-80 gets me 48-49mpg
5cyl. I managed to get to 38.7 mpg at 68mph. 80 mph and the mileage dropped to 31ish. 85 got me in the high 20's. This engine was really smooth and sounded awesome when you step on it!
The 1.8 turbo 4 gasser - I got a true 40 mpg combined at 68. 80 caused a drop to 35. 85mph netted about 32.
What does this prove? A diesel can get 35-40% better mileage than a gasser when driven in the same manner under the same conditions.
Also, as the speed increases, that percentage jumps to 50.
Even if you take the auto verses manual debate, it is still a significant jump.
Example two. My wife went from a Camry 4cyl to a Passat TDI with deg. And her average jumped from 25 to 45 mpg.
I used to make fun of diesels too! Now, I won't buy anything but.
Lastly, my aunt commutes in a Prius and a co worker in a Hyundai sonata hybrid. My aunt gets mid 40's around 75mph or so.
The sonata gets upper 30's at 80.
Both cost a small fortune.
I paid 24500 for mine. Plus I don't get the stigma one gets when they drive a Prius. That, to me is priceless. Lol
Sure, you may pay a few thousand more for a diesel compared to a regular gasser. But over time it pays for itself.
Buy a hybrid for even more and get the same or in most instances, less than a cheaper diesel.
There is a reason that the world mileage record belongs to, you guessed it, a Passat diesel! It got 78mpg or such. Try THAT in a hybrid!
Look it up!
The big missing point I think
Permalink
The big missing point I think is why is the fuel engine hooked to the drive system at all. Trains are diesel electric hybrid systems and have been for years. Their is no lost energy in the system . With a diesel generator changing your battery and electronic hubs driveing the propulsion you would see huge mpg boosts .
Diesels excel in situations
Permalink
Diesels excel in situations where hybrid isn't useful: On the open highway.
Gasoline hybrid for urban, diesel for the freeway. It depends on what your priorities are. Most of my driving is on the interstates. I have no use for a hybrid.
VW diesels meet emissions standards just fine, when they're not "cheating." They cheat in order to substantially beat the EPA's highway fuel economy numbers. Everyone who owns one knows that a TDI gets FAR better economy on the freeway than the government says it will. 60 mpg is possible if you behave yourself.
I'm currently looking for a late model "cheater", and when I'm forced to "fix" it I'm going to UN-FIX it as soon as possible. The "cheating" is a selling point for me.
If the goal is to achieve a
Permalink
If the goal is to achieve a zero or near zero carbon footprint car, the answer comes up as On-board power generation with a biodiesel driven generator. Since two/thirds of electric power on the grid comes from fossil fuel generation plants, plug in electrics are largely coal burners or fossil fuel burners. Not much gain for climate change there. The missing exhaust pipe ion the car is now the smokestack on the power plant down the pike. Biodiesel has a great future (CA already has 20 stations),and oo-board power generation has been around for a while.in locomotives.
It's a bit disingenuous to
Permalink
In reply to If the goal is to achieve a by Edward Hujsak (not verified)
It's a bit disingenuous to claim that 2/3 of our grid is powered by fossil fuels. That number depends heavily on your location.
Here in the western US, while we are still far from free of burning things, we are still leagues ahead of our east coast brothers with wind and solar taking over faster and faster. So an electric car out here, is much better than an electric car over in Appalachia.
It will still produce emissions through the coal and natural gas we have left, but it will still be a marked improvement over a hybrid, which is already a marked improvement over your average pure ICE car.
The internal combustion
Permalink
The internal combustion engine should never have been invented. Diesel (yes has a higher co2 footprint) has a future. It can run on 100% organic fuel with a simple conversion which could be designed into the fuel system. The engine doesn't wear itself out due to the constant lubrication of the fuel through all the moving parts of the engine.
Of course we should harness a different fuel source, but what we have now could be miles better in the right hands.
Our 2014 Diesel Cruz has
Permalink
Our 2014 Diesel Cruz has averaged 41 mpg combined since we owned it...about 13000 miles I have averaged well over 50 on many long trips. I owned a 2010 or 11 Prius once and had it averaging about 53 to 55 combined and had a few tanks average low 60s. I have seen diesel cost less than Regular Unleaded. Our Diesel Cruz would better the Prius if the engine would stop at stop lights and would do better yet if it could revert to a generate/battery at the same times a Prius can...
I believe that it's the
Permalink
I believe that it's the consumer that should decide whether to buy a hybrid diesel or gasoline, not the manufacturer.
I'd pay $5000 more for a hybrid diesel, no matter if it makes sense to you or not.
Diesel makes plenty of sense,
Permalink
Diesel makes plenty of sense, now with the lean / cleaner burning modern diesel motors becoming prevalent. What makes diesel look bad is that many of the vehicles they're being employed in are still old tech (HEAVY) build. The truck manufacturer that lightens their half-ton truck by 500+ pounds will be astounded by the performance gain for the diesel motor variants. All the torque of my EcoDiesel in a RAM that was 4500 pounds in stead of the more portly 5200 would be a truck nearly as fast as the Hemi 5.7 but with 22 / 30+ mpg instead of the current 19 / 28 (not bad either).
As soon as truck builders start seeing weight as the enemy and use advanced materials and build tech, then unladen mpg will soar.
It's now 2017 and I remain
Permalink
It's now 2017 and I remain baffled why there are so few series hybrids on the market (just the BMW i3 since the demise of the Amperage), and no diesels. Surely the mechanical simplicity and lower weight of series hybrids must outweigh any dynamic advantages of parallels?? And surely a small diesel running constantly at its most efficient speed will be more efficient than the equivalent petrol engine? I get 68mpg from my 1.6 honda, plus less anxiety about fire. Here in the UK diesel is only a penny a litre more than petrol but it would be good to see a cost-benefit analysis that factored out the differential tax levels pointed out above. Other factors are the extra cost of manufacturing a diesel, the extra weight of a diesel and its longer life span. Also the emissions question and whether the particulate problem can be solved. I'd love to see an informed debate along thermodynamic and engineering lines because I don't feel the question has been answered. Diesel electric works for trains, why not for cars???
Everyone seems to forget
Permalink
Everyone seems to forget during the diesel-electric combo that there IS a diesel engine which meets the CALIFORNIA emissions spec for several years to come. That engine is a micro-turbine manufactured by Capstone and puts out 30KW of energy. If we look at the TESLA car... it uses approximately a third of a kilowatt for each mile it drives, maybe a little more so let's call it half a kilowatt. That means we can go 60 miles on the output of the microturbine which during that hours worth of time uses approximately one and a half gallons of diesel. That works out to about 40 mpg with all the oomph and vigor of the TESLA S. with a reduced size battery on board which still allows for a fuel tank and meets the CA;emmisions which are being adopted by many states and the Fed.
So why not a large diesel-electric car? The trains have been doing it for years and they aren't using low pollution micro-turbines.
Just my 2 cents
Harvey
I think we need a different
Permalink
I think we need a different approach to diesel-electric for the auto industry. I believe we will eventually get to all electric vehicles, but we are still in the early adopter phase and it's a slow adoption curve. I think there is a middle ground where we can advantage of both technologies to cover the gap until we get to mass adoption.
I'd like to see a vehicle that was basically an EV that doesn't require the battery - it would use a small diesel engine only large enough to generate the electricity needed to power the electrical system. With the strides made in recent years on diesel engines, electrical converters and motors ... I think we could produce vehicles that would knock the socks off the standard options. We swap out the power generation from diesel to batteries when it makes sense (the battery technology gets where it needs to be - less rare earth metals, cheaper to produce, higher density, electrical distribution networks will support the masses, etc.).
My vision is combining a small efficient low maintenance diesel motor that acts as an electrical generator (maybe a two piston one cylinder AchatesPower OP motor) with an efficient electric converter and drive train package. If we put our minds to it, we could probably build it today with off the shelf parts and minimize the time to market.
We should be able to apply the concept to everything from small vehicles to large SUVs and scale the components as needed for the application. If auto manufacturers would do this, they would create vehicles with great longevity, low maintenance, and modular construction for lower cost repairs.
My two cents ...
diesel engines consume only 0
Permalink
diesel engines consume only 0.70 times the fuel gallons/mile so the diesel "real" fuel cost should be multiplied by 0.70 to get a feel for pricing comparison. Diesel vehicles used in underground mines have fitted excellent exhaust scrubber systems; the technologies are already here. If gasoline engines are so preferred why are "all" locomotives diesel/electric; it's because they can't be beat by gasoline types (gasoline has never been used). A diesel electric hybrid car is the only way to go; locomotive designers have known this for 100 years now. I have no idea why this technology is not yet common place. I can't wait for VW to build one that I can test drive for them here in Canada:) Battery function in cold weather will need to be addressed in the designs--Mike MacDonald, P.Eng. Electrical Drive Systems Specialist
As far as I know diesel cars
Permalink
As far as I know diesel cars provide lot better fuel efficiency. Where petrol/gasoline cars provide roughly 45.... diesel cars can provide easily over 55+ and gasolines are more flamable to fires.
Diesel will not disappear as
Permalink
Diesel will not disappear as refineries need an outlet for their products , Also even the Paris agreement does not restrict the use of diesel in commercial vehicles and the marine sector , which produce most of the pollution .
If the sale of diesel and plastic are restricted or stopped , refineries will not be viable , and many of todays products from oil will also disappear . The change has to be gentle .
Then there is the question what will governments tax when they lose the income from petrol and diesel , will they tax electricity which is already very expensive ??
I have owned VW diesels since
Permalink
I have owned VW diesels since 2009. My current (and probably last one) is a 2015 Passat TDI SEL Premium. I consistently get 37 MPG city, 42+ MPG Combo, and 54 MPG pure highway. Since VW has decided to no longer sell diesels in the US, I will just hang on to this one. It currently has over 100K miles. It runs, looks, sounds fine. All while giving me great fuel economy. While I acknowledge getting a bit old now (soon 70), I have not changed my driving habits since I was in my 20's. I would also like to state, I have NEVER had an issue with my 2L turbo diesel. How many people with gas engines can say that?
I personally believe, if done properly, a diesel/electric hybrid would be excellent. My son drive a Hyundai Ionic (gas/electric) and tends to average 56MGP. So while I am not as well versed on the buzz words as the author, I know what I see and believe if you take a diesel (~1.0 -1.4 L) and couple that with some of the electric technology, you will see a vehicle capable of doing 100mpg. Hard to prove or disprove when we can't get our hands on one in the US. Good luck to the rest of the diesel heads here....you will never convince a gas head our vehicles are great.
Climate Change is a hoax.
Permalink
Climate Change is a hoax. Makes one wonder if the government put stringent CO2 emissions to get rid of diesel to push their electric vehicles?
FirstHeritage offer loans at
Permalink
FirstHeritage offer loans at 2% interest rate.
Do you need a loan for business or private purposes?
Contact today for a corporate loan process.
info.firstheritageloans@gmail. com
WhatsApp: +1 (205) 852-6811
Sincerely