Wednesday, July 18, 2018

When car engines meet political correctness


Eric Peters blogs about the auto industry, and provides an insider's perspective on many issues.  His blog is worth following, if you aren't already doing so.  This morning, he takes on the issue of changing vehicle engine technology for the sake of fuel economy.

It is becoming practice to put undersized engines in oversized vehicles ... Today you pay [for this] in other ways [than just fuel economy].

Power/performance is one way.

The [Mazda] CX-9’s no-longer-available 3.7 liter V6 was much stronger than the turbo 2.5 liter four which replaced it – 273 hp then vs. 225 hp now, a difference of almost 50 hp, which is a difference with a distinction.

Another is stress  – and expense.

Undersized engines rely on turbo boost as the replacement for displacement. The theory is that you’ll use less gas when the engine isn’t being turbo-boosted. Which is fine – and true – when the engine is idling and the car isn’t moving.

The reality is that because the engines are too small (and not strong enough on their own) to adequately propel the vehicles they’re tasked with moving, they are on boost almost all the time once they’re not sitting still. The turbo boosts the power to adequate-engine levels, but also results in about the same amount of fuel being used by an engine that is working harder to make it and meanwhile, as a result, its internal parts are subjected to higher stress because of the higher pressure experienced inside a turbo engine.

An engine that isn’t turbocharged sucks air into its cylinder via the vacuum – negative pressure –  created by the pistons as they travel downward, inhaling (so to speak) the air that will be mixed with fuel to create the explosion which makes the power to propel the vehicle. A turbocharged engine is force-fed air, which is crammed into its cylinders under positive pressure (boost) which is typically in the range of 18-22 pounds per square inch.

Turbocharged engines can be built with tougher internals, to withstand the additional pressure – but the fact remains they are subjected to higher pressure (and stress) than engines which are not force-fed air. And no matter how tough-built they are, they are built with additional parts – the turbocharger and all its related bits and pieces. This adds certain expense up front – when you buy the car so equipped – and at least possible expense down the road, in the event a problem develops with the turbo and/or any of its related bits and pieces.

There's more at the link.

Another factor that he doesn't mention in this article (but has covered elsewhere) is that the modern, high-efficiency engines are designed and constructed for ease of robotic factory assembly and installation.  It's therefore almost impossible for a home mechanic to get at critical parts of them without almost disassembling the entire engine compartment, and/or removing the engine.  Even after he does that, without access to a computer and the necessary software, he probably still won't be able to do much more than change the oil and filters.  Maintaining your own vehicle has been almost purposely engineered out of them, forcing you to spend a great deal more money taking them to dealership workshops.

We're going to be buying a new (to us) vehicle within a year or so, as soon as our finances permit.  I'm not looking forward to the prospect.  I prefer to buy used, and pay cash;  but nowadays it's hard to be sure just how good a used vehicle is, and how well it's been maintained.  Even something so mundane as a cylinder pressure check is no longer nearly as simple as it once was;  in fact, the electronic monitoring and control systems on some engines will not allow you to run a compression check, because the necessary fittings must be occupied by a compliant device before the engine will start!  That's not a happy prospect.

I'm seriously considering whether to buy a ten- to fifteen-year-old large sedan (something like a Buick LeSabre or a Cadillac Deville) from somewhere like Florida, where they can be had for reasonable prices, and keep it running for another decade or more.  I'll have to spend more on maintenance, and perhaps a new engine and/or gearbox at some point, but that'll still be a lot less than paying inflated prices for new or nearly-new vehicles - and it will be maintainable!  On the other hand, Miss D. and I aren't getting any younger, and something with more comfort for older bones and less responsive backbones might be worthwhile, even at higher cost and/or more expensive maintenance.  It's a dilemma.

Peter

22 comments:

Pat Haney said...

Buying a ten- to fifteen-year-old large sedan (something like a Buick LeSabre or a Cadillac Deville) would probably be an enormous mistake.

I had an early 2000s Deville, and it was just about the worst car I've ever owned. The design is horrible. There's so much superfluous gadjetry that goes wrong, it's even harder to fix than a newer one.

I can't tell you how many times I said "WHY THE FCK DID THEY DO THAT?!"
I'll give you a few hints at what you are looking at with an old American car:

1. If the heater was on when I shut the car off, the fan kept running, depleting the battery. Who knows why? There's an ECM for the climate control, that appeared to be bolted to the wall under the dash.
2. There were a combination of 37 nuts, bolts, and screws to hold the water pump on. All different sizes and a mixture of metric and SAE
3. EVERY Gm car I've owned, I've replaced starters, alternators, and water pumps.
4. Those 15 year old plastic connectors on the wiring harness will snap when you go to remove them. The heat from 15 years of poor ventilation makes the wire insulation brittle.

I call my Toyotas the homely girlfriend that can cook. You learn to love her because she's reliable and so good to you. That caddy I called the flashy stripper with fake tits. When they get old, it ain't a pretty sight.

Expat(ish) said...

I would not buy an older car (10+ years), especially a FL car, for one simple reason: safety.

I'll be honest here, I was anti-airbag, then agnostic, now a big fan. And airbags have come a long long way in the last decade in terms of quantity, placement, and effectiveness.

Cars are also, god bless finite element analysis, safer literally every year. If you told me that a 2018 car was 25% safer than a 2008 car in any crash I would certainly believe that. This is a big deal, and an even bigger deal as we get older and take longer to recover from any injury.

Finally, I hate, hate, hate taking my car to a shop for a repair of unknown magnitude.

And lastly (see what i did there) I don't think the used market gives value for money anymore on a LOT of cars. A VW Passat with 40K miles is only $3K less than a brand new one? That's crazy.

My personal theory is that a car is an expense so I budget for it and part of that is what am I willing to pay for reliable and safe transport. Turns out that $20K is my number. The last $20K car (Passat) went for 13 years and 170K miles. Our minivan (Honda, $24K) has 9 years and 180K miles. We just bought a Golf Wagon ($20K) and I am hoping to get 10+ years out of that guy. And I expect these to be trouble-free years - once it's repair-a-month time we buy a new car.

That was rambling, hope it helps. I enjoy the blog, pls keep it up!

-XC

Beans said...

It's not just the engines. It's also the transmissions. My Ram Promaster City (which I bought because of seat height to ground and ability to load an electric wheelchair without using a derrick crane) comes with a nice 2.4l non-turbo engine but has a 9-speed tranny. There have been a couple times that the computer thought differently than what I thought was needed at the time.

I gave up on working on cars when you needed an advanced degree in 4th dimensional geometric engineering to even be able to understand how the engine works.

I secretly believe all the new auto-engine engineers come from the University of R'lyeh.

S L said...

Had a 2004 Infiniti M45. Only changed oil & filter,plugs and brake pads. 102,000 mi. no issues had air conditioned seats and an easy to work on v8(vk45de). Favorite car I have ever owned. Switched to a 2013 M37.

Nuke Warrior said...

A couple of thoughts:

"The turbo boosts the power to adequate-engine levels, but also results in about the same amount of fuel being used by an engine that is working harder to make it..." You would think there are some scientific principles that would explain this phenomena, oh yeah the laws of thermodynamics. Paraphrasing, The Zeroth Law-energy is energy, The First Law-the best you can do is break even (energy out can't be more than energy in), The Second Law-you can't break even.

Back in the sixties engines were massively over-built for the normal duty expected of them. Thus hotroders and Muscle car designers were able to get large horsepower increases using factory engine blocks without turning them into grenades (most of the time). That robustness was at the cost of added weight. Not a problem when gas was $0.25 a gallon, big problem when gas went over a $1.00 a gallon. Manufacturers cut the weight, cut the number of cylinders and switched from iron to aluminum. Part of this was the need to raise MPG to maintain sales. Then the government got involved and CAFE standards drove design to maximize MPG at the expense of nearly everything else. Thus we have smaller lhigher cars with smaller higher stressed engines.

tweell said...

I believe that you are overthinking this. Vehicles are much more expensive to purchase and repair, that's true. The upside is that they break much less often, especially if you drive 'sedately' (depending on the person, either 'not like a raving maniac' or 'like a little old lady') and do the proper fluid checks/replacements. It's not like you are able to be a shade tree mechanic any more, right?

Stay away from the turbo models and the first year of a new model, do a title search before buying that used car and get a mechanic to look it over as well, and you should be fine. Example: the Toyota Avalon is a full-sized sedan which has a 3.5l V6 engine. It should provide a minimum of 150k miles before any engine issues occur. If you get something with ~50k miles and drive 10k miles/year, it should last at least 10 years.

Now, how about that next Ames book?

bruce said...

Needing the turbo when accelerating is true, cruising on the interstate in Florida you won't need the turbo once up to speed. The fact is unless you are accelerating or going up a hill the turbo won't be needed.

The marvelous thing about newish cars is the ecu. I know its a computer and makes backyard mechs cry but it manages fuel to a fairly well. Drive behind any older car and inhale the poor fuel mixture caused by an out of tune carb or lousy injector system. That and the improved tolerances of modern car engines is a delight. Drive behind any older car and inhale the oil leaking past the rings. Walk in any garage with an older car and listen to your significant other bitch about wiping your shoes.

Sparrow Cain said...

Bought a 1980 toyota in 2004 now has 500,000 miles
Bought a 1985 cadillac fleetwood in 2008 now has 240,000 miles
Both cars run fine, they had all manner of parts replaced, as long as they got
Oil and water, transmission fluid in case of automatic, the things run forever ,if you check your fluid levels every morning, and don't let anyone work on it. Learn every part on that car like you know your gun and I bet you can fix anything. Would you let any one work on your gun? I know I wouldn't, not my gun not my car, not my house. Them are jobs there that you just don't trust to anyone , ever.


Love your blog.

Unknown said...

You may not have this brand in the States at all but we just bought a Kia Cerato and love it. It is without a doubt the best car weve ever owned. we paid about 15000 US for it. it has a 2 litre 4 cylinder naturally aspirated moto, 7 year unlimited warranty, roadside assistance included. 6 speed Auto and the amazing thing is that at a weight of about 3500 lbs plus we are getting between 40 and 50 miles per gallon. These cars have a terrific reputation. One of the Columns in an Australian newspaper says don't buy a BMW buy a Cerato. Our fuel costs us about $6.50 gallon so this is a terrific help to us.

deborah harvey said...

1997 mercury grand marquis with low mileage.
widows have them garaged.
will sell reasonably.
wish i could find another one.

deborah harvey said...

p.s. florida car. remember the hurricane and the drowned cars being passed off as good.

zuk said...

Don't rule out a minivan like the Honda Odyssey. They run well, are very easy to get into and out of, the power slide doors and power liftgate are awesomely convenient, and you can still carry stuff when you have to. It's not small, but has all the lux and convenience features of a luxury sedan. One a couple of years old will be suitably discounted.

My biggest issue with sedans is the (low) height of the seat, and the size and weight of the door. That said, if I was buying a sedan, the Mercury Grand Marquis gets my vote. My older parents have had several over the last couple of decades and love theirs. I love the size.

Differ said...

Last Oct wife and I drove the '13 Altima ATL to DAL and back. The following month repeated in 06 Mazda Minivan. The van is still WAAAY more comfortable despite and additional 100k miles on it.
Horses for courses I guess.

Marc Berte said...

A few comments:
1. Tensile stress, not compression stress, is what kills motors, and due to higher BMEP at lower rpm in a turbo motor, the critical fatigue life parts (conrods, crank) are actually subject to less tensile stress (which occurs at TDC on the exhaust stroke as that is peak piston acceleration @ lowest chamber pressure) and fewer stress cycles. So the higher BMEP of a equivalent power but smaller displacement turbo motor is actually not a longetivity factor.
2. If sustained boost were an issue for longetivity, turbodiesels wouldn’t exist in the overwhelming share they do. Yes, you have to build a motor more robustly, but since it’s smaller/lower # of cylinders, that’s easier and actually cost effective
3. The efficiency of a modern, properly designed (ie, properly intercooled, direct injection) turbocharged engine is greater under load than a NA engine due to higher overall effective expansion ratio

The dominant reasons for going turbo are cost more so than efficiency though.

The efficiency negatives and robustness negatives are mainly due to historical engines, not modern.

urbane legend said...

We bought a 2007 Chevrolet Equinox for the reason zuk mentioned. In our mid 60's getting in and out of sedans is way too much work. Has the GM 3400 V6, which been built forever and is as reliable as the sunrise. It is comfortable for travel. Averages 20 mpg.

Regarding BMW: My mechanic of 30 years says the BMW reliability stories are just that, stories. He says if one is cared for it will run as long as any Honda or Toyota, and parts are not nearly as expensive as people imagination.

Work on my own car? Why? I'm not good at, and don't want to anyway. I build my own guitars and speaker cabinets.

Beans mention of the 9-speed transmission is interesting. I talked to the owner of a transmission of shop who said the many speed transmissions these days have effectively become continuously variable units.

STxAR said...

I found a low mileage 99 Yukon 4wd. I can work on it, and have replaced a few things. I had one as a work truck, until I got T-boned in an intersection. With normal maintenance, it went 267,000 and was strong.

My current work van is a 17 Ford Transit e150. 6 speed transmission that is so complex they just replace them. The brain never down shifts it, so take off from a right turn is press harder on accelerator, more, more, more, sudden downshift to 1 and now it sounds like I'm a race car as the tiny engine zooms to 7000 rpm. Redline is 7500. It's a pile of dung. Unibody, no frame. I feel it twist on rough roads... The tires are spec'd to run at 64 lbs, so every bump in the road is felt, and every line is followed. Solid rubber might be softer....

The 90's GM vortec was a good engine to me. I've run work vehicles over 500K miles with them. The old 4L80 and to a lesser extent, the 4L60 in my Yukon are good transmissions.

I don't see how you could go wrong on a low mileage GM 99 or a bit older. They are still out there. The older Crown Vics, and Mecurys too.

Kriston Fincher said...

I have a 2008 XLR (Cadillac built on Corvette chassis) with 320HP NorthStar V8. It gets 32 MPG on the highway at 70-75MPH.

My dad has a 2008 Cadillac STS with the same engine, gets 27 MPG at the same speed (it's a heavier car).

My wife has a 2008 STS with the smaller V6. 24 MPG under same conditions.

Horsepower is not the biggest factor in gas mileage. Power and torque curves should cross at a reasonable RPM and the transmission should try to optimize for that.

Now as to buying a used car, you really don't know anything about how it has been maintained. The two biggest factors in engine life are heat and clean oil. In Texas I would only use specific racing oil, or full synthetic. A paraffin based oil (most of the cheaper brands) will break down at a lower temperature than others. This is what causes most "sludge" build up. This is more pronounced in the south and southwest.

GM did a test of oil on a dyno stand. They took two identical engines and ran one with standard motor oil, and the other with full synthetic. They were shut down at the proper mileage equivalent and the oil changed. They were to be tested to 200,000 miles. The standard oil engine almost made it before failure. The synthetic oil engine was then torn down and checked. All internal parts met spec to be used again.

If you check into a Caddy with the NorthStar, remember that GM will NOT honor warranty if you use non synthetic oil, but it is expected to be at least a 400,000 mile engine.

TwoDogs said...

I'm still driving a 99 Suburban that I've had since 2001. It has 140K on it and runs great. It cost me 5 or 6K around 7 years ago for transmission, air conditioning, power steering and coolant pumps and other issues, but has been pretty much issue-free since then. I'm gonna drive it into the ground and then find something used and Japanese.

STxAR said...

EDIT: That van redlines at 6750. My mistake.

Two Dogs has had very similar experience as I have with those years of GM.

My mechanic buddy at work warned me about the Northstar engine. The starter is under the intake manifold. If it goes, you nearly have to tear the engine apart to replace it.

YMMV.

Antibubba said...

Kriston mentioned the Cadillac with the Northstar engine. Worst car of the last 2 decades (with the possible exception of the PT Cruiser.

I work in an auto shop. The newest cars of the last 5 years are occasionally befuddling, and require you to almost relearn how to drive; I sometimes have trouble pulling them into the garage as I look for controls. As far as reliability and safety, you want to consider 2002 to 2012, especially in Japanese and Korean cars. There are some good American cars too. Euro cars are going to cost more to maintain, especially after 80,000 miles, which is when the first major maintenance items start coming. Volkswagens are decent. I would not buy a used Mercedes, BMW, Audi, or Volvo from after 1995.

Most of the modern cars don't need a tune-up until 90K to 110K miles. Think about that. Do you really want to be crawling under a car anymore, with all the injuries you have? If you do, or you want a "survival" car, that's understandable, but it will make you work.

Kriston Fincher said...

I would also like to point out that many of the newer designs shut off the engine at stops, and restart as you press the throttle.

With GM having noted problems with the starter, is that something that you really want?

Will said...

Another vehicle option you may have overlooked is the 4dr pickup truck. There was a serious swing toward creature comforts in these trucks around 2000 or so, as they were oriented toward family use in the lighter duty versions. The 2dr versions were generally aimed at work duty, so I would not bother looking at them.
The advantages of this choice is the ability to transport home maintenance stuff, and trailer towing chores. In the remote chance of a need to "bug-out", it affords a much greater carrying capacity.

One of the disadvantages of the cars you mentioned is the low driving perspective. So many of the vehicles in use these days are SUVs or pickups, that being able to see any distance ahead in traffic nearly disappears when using a car. That can be a real safety concern. Seeing trouble develop at a distance is much better for decision making. Time and distance for safety and security decisions is always better.