Fascinating CVVD Engine video

[RRoller123]

https://www.youtube.com/watch?v=uhsgdwUX1-w

Fantastic, he has a real talent to explain things that are actually quite complex.

Pete

[18Fiatsandcounting]

[rant on]
Great stuff, but please explain to me why my 1969 spider with the original 1438 cc engine (using 1950's engine technology) could get a solid 35 mpg on the highway at 60 mph, and today's cars, with all the electronics and modern technology and such, claim victory when they get somewhere close to that. And don't tell me that it's because my '69 spider didn't weigh much since, once you get the mass rolling, it's wind resistance and engine efficiency that take over, and not the weight of the vehicle, in terms of fuel efficiency. I'll grant you that driveability and emissions have much improved, but gas mileage, meh, not so much.

Jeez, a 1950s VW beetle could get well over 40 mpg... And here we are, 70 years later.

[/rant off]

-Bryan

[RRoller123]

The answer is that they are far cleaner and get a hundred, sometimes hundreds of horsepower more, and far more torque, out of approximately the same displacement, and right now those are greater marketing drivers than mileage, especially with gas prices this low. Almost any modern econobox will blow the doors off anything we drive here. But who cares? That isn't why we do it.

I wish there were some easy way to literally buy, say, 5,000 or 10,000 gallons of gasoline now, without taking delivery, and then fill it up a tank at a time at the local gas station over the next few years. That would probably be a great investment. Back in the early '70's, my friends out in Salem, Oregon bought a rural house with a 5 or 10K physical tank out in the front drive, and they would fill up their own cars. The property had been a small farm at one point. He being a Prof at Willamette, they didn't need it, so of course that went by the wayside eventually.

[18Fiatsandcounting]

Pete, I totally agree with you, and my previous comment was as much in jest as it was to raise a point. And believe me, I'm not at all suggesting that we return to the days of high emissions, engine rebuilds after 80K miles, periodic engine maintenance every year, poor running in cold conditions, etc.

I read somewhere that the energy contained in a gallon of gasoline, with no losses, would power a smaller sized car at around 200 mpg. Of course, there are losses such as heat out of the radiator and exhaust, drivetrain friction, rolling resistance, wind resistance, etc, and so in practice, a modern car could at best hope to achieve 60 or 70 mpg. Add in AC, larger cars, more HP, more electrical amenities (which require power to recharge the battery), and that operational efficiency drops to 30 or 40 mpg.

OK, I've derailed your original (interesting) post far enough, so I'll stop there.

-Bryan

[RRoller123]

My '79 X1/9 got 30 mpg, over the whole tank, i.e. start and stop, highway, etc. but made all of 78 HP, hahahah!

My 2011 Malibu 4 seater sedan did 36 mpg on our FL trip, round trip, and it is much faster than the X1/9.

But who cares? We have way more fun in our little Spiders, yes!

[SteinOnkel]

[rant on]
Great stuff, but please explain to me why my 1969 spider with the original 1438 cc engine (using 1950's engine technology) could get a solid 35 mpg on the highway at 60 mph, and today's cars, with all the electronics and modern technology and such, claim victory when they get somewhere close to that. And don't tell me that it's because my '69 spider didn't weigh much since, once you get the mass rolling, it's wind resistance and engine efficiency that take over, and not the weight of the vehicle, in terms of fuel efficiency. I'll grant you that driveability and emissions have much improved, but gas mileage, meh, not so much.

Jeez, a 1950s VW beetle could get well over 40 mpg... And here we are, 70 years later.

[/rant off]

-Bryan

If you are looking at straight MPG, sure, the older cars can still compete. Although I doubt a 50s bug gets 40+mpg. Maybe 30+.

But your modern car weighs 2-3x as much, because of safety features. If you're in an accident in anything 20+ years old, you are screwed. A more fair comparison would be comparing an old American car, they weigh about the same. And their mileage is atrocious.

Also, as a side note, the Derby gets 45mpg cruising. It has the best of both worlds, modern(ish) engine, modern computer, but it's super light. Stock was around 30mpg, and that was with 1/3 the horsepower

What you're driving at in the second post is the thermal efficiency which Jason also has an excellent video on. The modern gasoline burner is around 35% efficient, a modern diesel more like 40-45%.

And an electric motor is 99% efficient...so you can guess where the future is headed.

Cheers
Steiny

[18Fiatsandcounting]

No disagreements from me, Steiny. Just thinking aloud, and again, I'm not lobbying for a return to the 60s and 70s. Rock music, now that might be a different story...!

-Bryan

[rridge]

Bryan,

Sometimes when we are waxing nostalgic about the good old days of things automotive it is helpful to go back and read some old road tests. Below is a link to a 1965 Road&Track road test of a VW 1200, perhaps the most numerous of all the Bugs sold in the U.S. The mileage they got in their testing was 26-28mpg. That is consistent with my own experience. It's engine technology dated back to the late 30's and technology had moved on even then as it always does.

Zero to 60 in their testing was 29 seconds, or just a bit faster than a 2CV. With some care and the excellent VW dealer support network you could get 100,000 miles out of an engine. But when you pulled it for an overhaul, there often wasn't much of the engine including the case and crank that were worth saving. Here's the link: https://www.oldspeed.net/articles/image ... ge50_g.jpg

[18Fiatsandcounting]

Thanks for that reference. Believe me, I'm not disagreeing with anything posted so far, nor I am longing for the good ol' days. I just think that other things have become more important in cars in recent decades, such as emissions, driveability, more power, more accessories, more weight, versatility, durability, etc. Although fuel economy is often touted as important, when it comes down to it, most people choose the above list of factors more than they do fuel economy. I'm guessing that when gas is cheap (as it is now), fuel economy isn't very high on the list of buyers' considerations. Manufacturers respond accordingly.

Just my $0.02, and of course, your (gas) mileage may vary!

-Bryan
PS: When the engine in my '69 spider was original, I could go just slightly over 400 miles on the highway on an 11.2 gallon tank . So, around 36 mpg. I've calibrated the speedometer against mile markers on the highway, and it's pretty accurate. Of course, those were the days when I was a poor starving student and it was often a choice between lunch or gas money, and so I had a lithium foot rather than a lead foot.