Annoying VW Diesel...

Yes I do hate it, maybe in a different way, when an old smelly noisy diesel like mine gets as good as or better fuel mileage than a Prius. My 1985, yes 85, VW diesel gets 55mpg consistently on the highway without any modifications. My diesel is based off the 1975 VW diesel Rabbit, so it's at least a 40 year old design! And yet I can't seem to get less than 50mpg in it! If I'm easy on the pedal I can get over 60mpg! over 30 years later and my options are... about the same fuel mileage (in a Prius). Ok, so power, safety and emissions have improved. But why not fuel mileage? This drives me nuts! Every car dealership I've been to wants to talk me into buying a car that gets half of what my 30 year old diesel does. I want a car that gets better fuel mileage! What happened to the 125mpg Aptera? Why was the 250mpg XL1 never sold in the USA? Why does everyone want a crossover or SUV? This is insane!

Add to that that my diesel is immortal. I've got over 500,000 miles on the thing and it just won't die. The maintenance is also very low. Just oil and filters and the timing belt from time to time. It's like the Energizer Bunny. It just keeps going and going and going.

I'd like to replace my VW diesel, so I'm contemplating a Prius, which is about the only car that makes sense for me right now. But I'll be getting about the same fuel mileage. And both diesel and gasoline are about the same price around here, so no benefit there. And every 10 years or so I'll have to replace the expensive traction battery; not to mention things like sparkplugs, sensors and catalytic converters. So all in all a Prius will cost more to own and operate, which I guess is a fair trade for better emissions and safety.

But I also have my doubts that after 30 years and over 500,000 miles a Prius will still be as running as good as it did back brand new like my diesel does. So I better get my mind wrapped around the idea of a disposable vehicle. And overhauling a Prius is likely out of the question. If my diesel blew up tomorrow I could rebuild the engine myself and have the transmission rebuilt. I could put in new or refurbish my own brake and suspension parts and drive the car another 30 years. And all that for less than the price of a used Prius! But once things start to go out on a Prius that's the end. It will probably be electrical problems that will be it's demise. Trying to track down which wire, sensor or ECU is failing after 500,000 miles would be a nightmare for me on a Prius. On the diesel there are only 40 electrical components that are needed to operate the engine. 1 the alternator and battery, 2 the starter, 3 the glow plugs and 4, the shut off solenoid.

Why can't they make cars that get better fuel mileage than 50-60mpg? Why can't they make cars that last without needing expensive maintenance and repairs?

Still, I want better emissions and air conditioning. So it's Prius or bust right now for me.

 

Not a diesel...but I loved my Honda Civic VX back in the day. Stellar MPG. However, it was a horrible NOx polluter.

 

Because all of the extra safety features and design considerations add lots of weight, which burns a lot of fuel. The cars are way more efficient today in pound hauled per mile type figures.

A 1985 VW Jetta diesel weighs 2200lbs. A 2018 VW Jetta Google tells me is 3200lbs. Almost 45% more vehicle.

Then also keep in mind that 1 gallon of diesel has 13% more energy in it than 1 gallon of gasoline. And you can't buy 1 gallon of gasoline in a 1 gallon container. Best you can do is E10 usually which is 10% ethanol, which is crap. In the winter it is even worse with all the additives and "winter blend".

The GGE numbers say that a gallon of summer E10 is about 98% equivalent to a gallon of gas. And that a gallon of diesel is 113.6%.

This means your 50mpg diesel is using the equivalent energy of a 43mpg gasoline vehicle. So to get a vehicle with higher efficiency that is gas burning, a 44mpg vehicle is better right off the bat.

Nissan a couple years ago did a crash test between a 2016 Versa and a 2016/2015 Tsuru. The Tsuru is basically a 1991 Nissan Sentra that is still being manufactured brand new. Similar-ish to your 1985 vehicle. The 2016 modern car that crumples does a good job of protecting the bags of flesh that would be inside. The 2016 death trap based on 25 year old tech becomes a final resting place.

This is why fuel economy today is lower. The cars are 50% heavier yet achieve equivalent or better fuel economy. That's pretty good.

As to price, cars are the same or cheaper than they were. That 1985 VW Jetta was $8K base in 1985. In 2018 dollars, that's $18.5k in today's dollars with inflation. Looking online, a 2018 VW Jetta base MSRP is $18645! For the extra $145 think of all the extra luxuries and comforts, technology, safety, and even better paint jobs you get today. Cars today are super reliable you expect them to go 100k miles without even thinking about it. Getting 100k miles out of most 1980's vehicles would get you a hardy laugh from your mechanic unless you constantly tore it down and rebuilt it.

So apples to apples, todays stuff looks pretty good.

 

Yes, they weigh more which causes more rolling resistance and lost momentum during braking. But note that weight isn't the main thief of energy; it's aerodynamic drag. New cars are much more aerodynamic than ever before. When cruising down the highway the amount of energy lost due to weight between my ol' Golf and a brand new Prius is not that much different. Yet the aerodynamics on a Prius are much better. Granted, newer cars are bigger, which adds more drag. But all in all, I would be willing to bet that you wouldn't get better fuel mileage in a vehicle that had the drive train of a Prius and weight and shape of an 1980's Golf.

Also add to that that most of the cars getting that kind of fuel mileage are hybrids, which also isn't a fair comparison, except on the open highway where the electric drive isn't being used. There is the Mitsubishi Mirage that gets and EPA rating of 46 or 47mpg (IIRC) that isn't a hybrid, so that's about the same efficiency as 40 to 30 year old VW diesel.

Yes. that's true too. But remember that diesel energy also drops with it's winter blend, so much so that winter diesel and winter gasoline can have about the same energy amount. Which is why I get around 50mpg in the winter, but more than 55mpg in the summer.

50mpg is my worse fuel mileage. I normally get above 55mpg, going highway speeds and driving normally and 60mpg if I'm easy on the throttle. So no, the gasoline car would have to get between 49 to 53mpg to beat my 'ol Golf in efficiency. Which can be done, you're right. But there also have been cars that get 3 to 4 times that efficiency, and yet aren't being sold. That tells me that even better efficiency is possible.

And there is one thing that can be said about internal combustion efficiency, diesel has the potential of being more efficient, period. Yes, gasoline efficiency has increased, and we have to account for diesel fuel having more energy than gasoline. But there's a lower limit on how efficient gasoline can be. For one, the compression ratio can be made much higher in a direct injection, lean stratified charge engine like a diesel. And two, there are no throttling losses in a diesel engine. And ironically, you can increase the efficiency of a gasoline engine by using a direct injection and a lean stratified charge, but then you end up with the same emissions problems you get in a diesel.

And there is another thing to be said about diesels. Longevity. If you start a gasoline engine cold, fuel gets on the cylinders and washes the oil off. But diesels don't do that. And even if the fuel doesn't burn and gets on the cylinders, diesel fuel is a much better lubricant than gasoline.

But regardless, yes you are right about a lot of things. But it still doesn't mean that fuel mileage has improved by leaps and bounds. The 1940's VW Beetles were getting over 30mpg. Yes, the Prius and a few others get much better than that. But I still know a lot of people that are impressed if your car gets over 30mpg.

 

Yes, each car has its own pros and cons. But if a diesel gets better fuel mileage and costs less to run on the highway, then you could say the diesel is a better highway vehicle than a gasoline hybrid, and the hybrid is a better city car.

I'm interested in a Prius because I have to drive some 150 miles in a day and want good fuel mileage, better safety, better emissions and A/C. But I'm coming away from a 1985 VW diesel that already gets around 55mpg even over steep mountain passes, has no issues with having a cold or hot traction battery especially on those -40°F days that we get in the winter, is not affected by overcharging a traction battery from coming down off mountain passes a total of 10,000ft in a single day, and has lasted well over some 500,000 miles without any major repairs. So I feel like although going from an old diesel to a newer gasoline hybrid will be an improvement in some areas, in others it may not be for me personally. Will the Prius still get me some 50mpg or better when it's way below zero? Will I have traction battery problems in the near future from going up and down such steep mountain passes? How often will I have to change the traction battery with the mileage I'll be putting on the car?

So for us highway drivers is a hybrid really worth it? I think it should be. I guess I'll find out. However, at the same time I would jump on a non-hybrid if it got some 50mpg or better. But such a car just doesn't seem to exist unless I get an emissions scandal VW diesel.

 

Is a hybrid similar to the Prius but running on diesel viable?

 

I went from TDIs to a Prius and I didn't miss the diesels at all. The highway fuel mileage was close enough on the Prius and the gas was cheaper than diesel. I didn't have to bother with additives, either.

 

Definitely possible. Would probably cost a bit more though. The only diesel hybrid car that I know of, however, was terribly expensive. The VW XL1. But it also got 250mpg on diesel fuel alone!

Thanks! One question. What octane grade do Prius require? Diesel is about the same price as midgrade around here

 

This may be really wrong thread, but VAG Group has another "great" thing going on: For example VW Polo has three positions on the back seat and there is possibility that middle seatbealt lock can open seatbealt on the left on accident.
They came up with the fix: Ziptie.

On the local Magazine test(finnish language) in Finland the ziptie broke at minor breaking so it makes possibility that in accident that first is breaks and when car continues rolling etc, then it opens seatbelt lock on the another passenger and then that person is without seatbelt.

I just cannot believe these guys… "ziptie was VW sertified fix for this"...blaa blaa..

 

Just regular.

 

They run on regular.

 

So it would be a bit cheaper that way too. Good to know. I definitely am trying to go from my old VW diesel to a newer Prius, so this kind of info helps! Got to sell my cars first though so I can have the money.

 

Technically, yes.
Economically, not likely. Unless the cost for diesel emission controls drop. And then the cost of a full hybrid system might not be worth it.
A diesel ICE is already more efficient than the gas one. So the times of engine off operation will increase the overall fuel economy less than in the gas model.

 

Yes and no. There's a lot of factors that could make it worth it or not. Of course those that would benefit from a diesel hybrid would likely be a small crowd. So basically, you're right on!
Ideally you want an internal combustion engine that only runs at the most efficient RPM and load/throttle level that it was designed for. And usually that happens close to, or sometimes at full throttle. (Which is why smaller engines and taller gears tend to increase efficiency by making the engine run at a higher load without causing more losses than gains through higher speeds). But if you design an engine like that (one that is always running at full throttle), then you either have to pulse and glide to keep your speed down or you end up with an engine so small that it only produces enough power to maintain a steady highway speed, but wouldn't be able to accelerate and climb hills.
But a hybrid has the advantage of accelerating the vehicle with two types of motors (or "a motor and an engine" for you definition sticklers.) Because of that, the internal combustion engine can be designed more for efficiency and less for power. The more electric backup you have to take over in those situations that you don't need average power, the smaller and more efficient the internal engine can be designed.
Now a diesel engine can be more efficient than a gasoline engine. According to CR's highway tests, the 2018 Chevy Cruze diesel gets 60mpg whereas the 2018 Prius gets 59mpg. That's pretty close in efficiency (technically the Prius engine delivers more miles on less energy since gasoline has slightly less energy than diesel). But the Cruze's 1.6L diesel engine is designed to output a max of 137 HP whereas the Prius's gasoline engine will only deliver 50 HP max meaning the Cruze certainly runs much farther from it's ideal engine load than the Prius. Imagine if you took that Cruze diesel engine and shrunk it to only 50hp max like the Prius engine. Undoubtedly efficiency would increase by quite a bit.
An interesting comparison is one between the Aptera and the VW XL1. Both are plug-in hybrids with the focus on making them as aerodynamic as posible. The main difference is that the XL1 has a diesel engine instead of a gasoline engine. And yet it gets 250mpg on diesel alone (no plugging in) whereas the Aptera only got 125mpg. That's twice the fuel mileage and almost twice the efficiency! Imagine a diesel Prius that gets 120mpg! Well, you probably won't get 120mpg in a diesel Prius seeing all that has been done to increase the efficiency of the gasoline engine. But 75mpg or more would likely be possible.
But yes, the overall costs would be more. Diesel engines cost more than gasoline engines to manufacture, especially with the modern day emissions equipment they require. And hybrid systems cost more too. So you'd be sticking two higher cost factors into one car. So if the gasoline car costs $15,000 and the hybrid or diesel costs $25,000 then the hybrid diesel is going to start out at $35,000. You might as well as buy a Tesla for that price, or at least a Prius with all the bells and whistles. Getting 75-90mpg vs. 50-60mpg isn't going to pay off any time soon unless you do a whole lot of long distance driving.
But everyone's situation is different. I need to go 150 highway miles per day. That puts a Prius and a Chevy Cruze diesel neck in neck for me. Diesel's are also known for longevity. Lot's of big trucks have well over a million miles on them, and they owe that to their diesel engines. My own 55mpg 1985 VW diesel Golf that I'm thinking about replacing has over 500,000 miles on it, and is showing no signs of wanting to die on me anytime soon. This diesel car is immortal! It makes me stop and think twice about whether I really should replace it or not.
However, if I do buy a newer car it would be a Prius and not a Cruze because of Toyota's reputation for reliability and the fact that I can get $9,500 in tax credits here in Colorado if I buy a new Prime. But if Toyota offered a small diesel car here in the USA I would seriously consider it. And if they offered an economically priced diesel Prius... Hey! I can dream can't I?

 

You obviously love diesels. Go find one and buy it. Be happy. If you buy something else, then all you're going to do is keep looking back and doubting your purchase. Find a nice one that you like, buy it and roll on, get on with life.

 

I don't love diesels. I just see advantages and disadvantages, and try to be open minded. Plus, if I want to be happy I better get what my wife likes instead!

I like certain diesels for certain reasons. I also like certain gasoline cars, certain hybrids and certain electric cars for many different reasons. In fact, since November of 2016 to June of 2018 I actually owned three cars: one gasoline, one diesel and one electric. And I liked them all!

The diesel, a 1985 VW Golf, has always been "Ol' Faithful." In the past 8 years or so that I've owned it this car has never given me any major problems, even though it's over 30 years old and has over 500,000 miles on it. The car seems to be "immortal", and just keeps going and going, and gets up to 60mpg on the highway at the same time. I have never hesitated to take it on very long trips, including over a dozen 1,500 mile round trips to my mother-in-law's. If only it had AC, looked a bit better and didn't leave black clouds of death behind me as I go up steep mountain passes, it would be a nice car.

But the electric, a 2013 Nissan Leaf, was even better at not giving me any problems at all. And for what I pay for electricity, it was the same as getting 120 mpg along with many fuel stations that give free fuel. I did a 700 mile round trip in it basically for free. That was the car I really wanted to keep for as long as possible. But the problem is that I now need to drive some 150 miles or more per day, so it's time to say "goodbye" to the electric car.

I've owned only one diesel car and one electric car, but have owned over a dozen gasoline cars in my +20 years of driving, including 4 Toyotas, 2 Nissans, 1 Honda and 1 Mazda. The one that I liked the best was my 1993 Mazda 323. I would get about 45 mpg on the highway with that car and made it to Puerto Vallarta and back with no problems other than the trunk filling up with rain water.

Anyhow, the goal is now to simplify down to just one car, one good car. With needing to go 150 miles per day (over 30,000 miles per year) I don't want to waste my money on the first car that is waved in front of me. I have no bias towards diesels or electrics, nor to brands I've had success with in the past. I know what the technology is capable of, but that doesn't mean if I get a diesel I'll be happy. For the past few days I've been reading front to back the April 2018 edition of Consumer Reports about "Best and Worst Cars." The Chevy Cruze diesel is about the closest I can get to a diesel car that I would buy. But the numbers point to it as being more expensive and less reliable than a Prius.

To me, the most important things are:

1. Initial price. If two cars last me 100,000 miles or 3 years, but one costs $30,000 and the other $15,000, I'll be paying $5,000 less per year on the cheaper car in car payments alone.
2. Longevity and reliability. If one car lasts 100,000 miles or 3 years and the other 200,000 or 6 years but both cost $30,000, then one will cost me $10,000 per year in car payments and the other $5,000 per year if you average it all out.
3. Fuel mileage. If one car gets 30 mpg and the other gets 60 mpg, I could be spending some $3,500 less per year on the 60 mpg car.

So far that seems to point me to a new Prius Prime, perhaps a new 2017 model for around $25,000. With the $4,500 federal tax credit and the $5,000 Colorado tax credit, that knocks the price down to some $15,500. The Prime should last at least 200,000 miles before needing major help, and may get way more than that as long as I take care of maintenance properly. A couple perks are that I already have a charging station attached to my house and I know where all the free charging spots are so I can charge the Prime off super cheap electricity. That will help me get even better fuel mileage than any diesel out there. And unlike an all-electric, the Prime can do gas anytime it runs out of electricity. And unlike something like a Chevy Volt, once it goes to gas the Prime will be getting stellar fuel mileage.

Yes I like diesels. But unless you can point me to a diesel car that costs $15,000 or less, has the longevity and reliability of a modern day Toyota, gets the emissions it should actually get and has A/C, I'm not buying a diesel.

Diesel technology is capable of doing all that and getting 250 miles per gallon at the same time. But that doesn't mean that 250 mpg diesels are found all over the place waiting to be picked up for next to nothing.

 

More than likely your XL1 and Aptera comparison is not a like to like. The XL1 was only offered in Europe, so any published numbers are based upon NEDC tests. These are easier, lower speed tests than what the EPA uses in the US. The rav4 hybrid is rated 55mpg on it vs the 30mpg on the EPA window sticker. Considering past favoritism for fuels, it is possible that NEDC has a bias for diesel(the EPA may have slight bias against it). Europe does have separate emission limits for diesel and gasoline cars. The XL1 won't meet US emissions, and doing so could reduce its efficiency.

The Aptera never came to market. Assuming the 125mpg figure was from EPA test cycles, the results were never certified. Either way, the two cars were tested under different conditions.

Ford had two full hybrid diesel concepts in the early 2000's; the Reflex and Meta-One. IIRC, they qualified for the cleanest emission bin for an ICE car at the time. The Reflex was stated to get 65mpg. That was from before the major adjustment to EPA testing and window sticker values. The gen2 Prius was rated 60mpg city/51mpg highway/55mpg combined back then.
Ford Reflex - Wikipedia Mercury Meta One - Wikipedia

When asked about the powertrain of those concepts being used in a consumer car, Ford said no because it cost $9000. Considering the advancements made in hybrid cost reduction, such would likely cost maybe $5000 today. Considering the likely gains over a gas full hybrid or diesel, too few people are willing to pay that extra cost.

Now a diesel with a mild hybrid system might be viable financially. The Cruze diesel already has a start/stop system standard.

 

Here's another thing I don't like about stinky VW diesels and Prii.

So I go on the ol' stinky VW forum and post that I'm thinking of changing out my ol' diesel for a Prius. The car still is doing well at getting good fuel mileage and also keeps being reliable and easy to maintain. It even looks like it'll go another few hundred thousand miles, no problem. But it doesn't have AC, any safety features, the paint and interior are shot, and it needs a lot of rust repair. So I'm thinking Prius since a Prius seems to be the only modern car that gets great fuel mileage and is reliable and will last a long time like my ol' stinky diesel has, and all that without the emissions scandals and reliability problems newer diesels are having. Other VW fans say that's ok. That perhaps it's time to move on. There's nothing wrong with that.

Then I come to the Prius forum for support and help getting a good Prius. And so far I've been told by many not to get a Prius. I've even been told to just stick with my ol' stinky VW diesel. That the Prius won't do what I want it to do. That the Gen 4's haven't proven themselves and cost way more than what I'd save in fuel. That the Gen 3's are sucking oil before 100,000 miles. That the Gen 1's and 2's won't do me a bit of good since I live in the mountains and where it snows quite a bit.

I still feel like I should get a Prius. But I feel a bit discouraged. I'm quite confused.