The hybrid ticking time bomb

[JSH]

Originally Posted by Ecky

Off topic, but adopting a higher base voltage (24 or 48) would likely measurably improve non-hybrid vehicle efficiency. I understand why it isn't done, but at some point that bandaid may need to be ripped off.

I can speak directly to that. The reason we aren't running 48V electrical systems is cost. Yes, engineering says 48V makes sense but the economy of scale on 12V systems is so large that you can't make up for the higher component price with efficiency.

We are slowly seeing the transition with the rise of mild hybrid systems but in that case you also get a big boost in efficiency to offset the extra cost. Eventually the product mix will change enough so that 48V is cheaper.

[Isaac Zachary]

Originally Posted by Ecky

This is correct that the hybrid system itself is only a piece - although my new Miata (MX-5) does in fact run the Atkinson cycle without a hybrid system. It does this with complex, sensitive and highly responsive engine control.

That may be true, but also to what degree? The Freevalve engine is supposed to run nearly all the time in an atkinson cycle, but at WOT bascially goes into an Otto cycle. However, the whole time it has the same compression ratio. I suppose the same can be done with variable valve timing on any engine. But again, the CR doesn't change. On a Prius the CR is extremely high, but is compensated by the engine always running in an Atkinson cycle.

Originally Posted by Ecky

A modern Jetta will achieve 40-45mpg at 75mph. I'm personally ignorant about these old air cooled engines, but I don't imagine that stock Beetle was getting 40mpg at anything above 40mph - a speed at which a stock Insight will happily cruise at 120mpg, apples to apples.

The 1979 Super Beetle had a highway fuel mileage of 30mpg. The 2003 Digifant Beetle (Mexico) was rated at 32.5mpg (although I think that's combined, I remember highway being like 38mpg). Some have claimed to get up to 40mpg through mods and hypermiling. I got 30mpg on the highway in my 1972 Super Beetle. Other body designs using the same engine got better fuel mileage (e.g. Karmann Ghia).

[Ecky]

Originally Posted by Isaac Zachary

That may be true, but also to what degree? The Freevalve engine is supposed to run nearly all the time in an atkinson cycle, but at WOT bascially goes into an Otto cycle. However, the whole time it has the same compression ratio. I suppose the same can be done with variable valve timing on any engine. But again, the CR doesn't change. On a Prius the CR is extremely high, but is compensated by the engine always running in an Atkinson cycle.

Just about all the time, really. It's a non-hybrid with a 14.0:1 compression ratio, so it's bleeding off a lot of that cylinder pressure through the Atkinson cycle, while keeping the expansion ratio, even with the throttle wide-open. Tuning it for power is basically an experiment in seeing how little you can bleed off at WOT.

By comparison, the 4th gen Prius only has a 13:1 CR, and the Freevalve engine is only 9.5:1 - though that one has around 30psi of boost.

EDIT: It's a bit beside the point however, when both Honda and Toyota have engines with lower compression and higher thermal efficiency.

Originally Posted by Isaac Zachary

The 1979 Super Beetle had a highway fuel mileage of 30mpg. The 2003 Digifant Beetle (Mexico) was rated at 32.5mpg (although I think that's combined, I remember highway being like 38mpg). Some have claimed to get up to 40mpg through mods and hypermiling. I got 30mpg on the highway in my 1972 Super Beetle. Other body designs using the same engine got better fuel mileage (e.g. Karmann Ghia).

Surprisingly good. I wonder if part of that is not having a bunch of parasitic accessories like water pumps and power steering.

Fuelly seems to suggest real world mixed driving economy is a bit lower:

https://www.fuelly.com/car/volkswagen/super_beetle

Reading Quora, most owners there suggested they were seeing 25-28 highway.

The median is ~23mpg, right around what a new F150 gets in mixed driving.

That said, I 100% understand the appeal of having an engine with no electronics, that you can rebuild for $200 - even if it needs that rebuild every 75-100k or so. So long as rust doesn't take it, that's a vehicle that doesn't have an expiration date.

[freebeard]

Originally Posted by Isaac Zachary

Some have claimed to get up to 40mpg through mods and hypermiling. I got 30mpg on the highway in my 1972 Super Beetle. Other body designs using the same engine got better fuel mileage (e.g. Karmann Ghia).

Hot VWs magazine did their Mileage Motor and fell just short of 40MPG at 65MPH.

https://www.thesamba.com › vw › forum › viewtopic.php?p=3760272
TheSamba.com :: Performance/Engines/Transmissions - View topic - Hot vw ...
I was scanning some of the HVWs articles on CBs site and also re-read the original Jon Karcey mileage motor article. HVWs original goal was 40+ MPG. The best they got was 38.46 MPG @ 65mph before they started fooling around with fuel injection voodoo from CB where their mileage dropped back down into the 36 MPG range.

Note the name John Karcey. I prolly still have the original VW Greats article wherein he got his Karmann Ghia to [an unofficial] 50 MPG.

The Volhart-Sagitta (my spirit aniimal) did 90MPH on 25HP. I've never seen mileage figures for it. It had a Cd equivalent to the Prius.

That said, I 100% understand the appeal of having an engine with no electronics, that you can rebuild for $200 - even if it needs that rebuild every 75-100k or so. So long as rust doesn't take it, that's a vehicle that doesn't have an expiration date.

I bought and sold my 1979 Dasher with a defective oil indicator light. It had an LED on a flexicable. With the Beetle, if the body rusts away, it's like 'Oh well, anyway..."

[Piotrsko]

freebeard: you have more VW experience than I. What rusts on the body that isnt replaceable except for the door hinge mounts? I know you can get a whole pan in a kit.

Pretty sure an engine reman kit is more than $200 anymore, but maybe thats rings and seals only, bearings are good for at least 150 k miles

With the solex, best I ever got was 27 mpg in the 72, never cared about mileage in the other stuff

[Isaac Zachary]

Originally Posted by Ecky

Honda's OEM batteries stopped being from the original supplier after 2010ish, and became hardly better than aftermarket - probably because they used the same cheap Chinese cells, because the original Japanese ones simply did not exist anymore. After another 5 years there simply wasn't an OEM battery to purchase, period.

With both Gen2 and Gen3 Prius batteries being marked as "unavailable" on Toyota websites, there seems to be a chance the Prius has taken the same route.

[freebeard]

Originally Posted by Piotrsko

freebeard: you have more VW experience than I. What rusts on the body that isnt replaceable except for the door hinge mounts? I know you can get a whole pan in a kit.

Nothing. You can get entire bodies in white. But metal work and paint are expensive compared to gel-coat fiberglass.

Pretty sure an engine reman kit is more than $200 anymore, but maybe thats rings and seals only, bearings are good for at least 150 k miles

Back in the day the parts were $450. I have a complete 1776 on the bench but it would cost $1500 to have a mechanic put it in the Superbeetle (1 5/8" exhaust, etc.).

Last time I tried to jack it up myself high enough to get the motor out (other reasons) it fell off the jack and broke a Type III worm-drive jack. I consider a two-post lift indispensable.

[S Keith]

Originally Posted by Isaac Zachary

With both Gen2 and Gen3 Prius batteries being marked as "unavailable" on Toyota websites, there seems to be a chance the Prius has taken the same route.

This is absolutely, positively untrue and Honda's history has ZERO correlation to Toyota past 2005. Very few websites actually sell batteries. If they're out of stock, they're going to show as unavailable.

Toyota is simply dealing with a massive supply problem. NiMH modules that go in new cars also go in new replacement packs - there is no difference. They're going to prioritize packs for new cars over replacements.

Go put one on order with a dealership, and you'll get it in about 4-6 weeks.

History lesson:

1990s: Panasonic EV energy formed. Panasonic/Toyota partnership.

Gen0 Prius, 97-00 - only in Japan. used the same "D" cell "bamboo sticks" that Hondas used.
Gen1 Prius, 00-03 - Ditch "D" cells in favor of new prismatic module. They had substantial problems with module leaking at the terminals.
Gen2 Prius, 04-09 - Redesigned module. Doubled internal interconnects for lower module internal resistance and fixed terminal leak issue (slightly longer than Gen1 modules). Reduced module count from 38 to 28 as the higher voltage was no longer needed for reduced current due to the improved internal resistance.

2005 Honda moves away from Panasonic EV Energy and starts using Sanyo cells.

In other words, from 2000-2005, Toyota made the batteries for Honda.

2006: Honda designs the 2nd worst hybrid battery ever made in the 06-08 Civic. 16% failure rate in 4-6 years.
2009: Honda designs the worst hybrid battery ever made in the 09-11 Civic. 30% failure rate in 2-3 years.

08-09 timeframe. Panasonic acquires Sanyo. To address regulator's monopoly concerns, Panasonic mostly divests itself of its partnership with Toyota, holding only a 20% stake.

2010: Panasonic EV energy renamed to Primearth EV Energy. 80% Toyota, 20% Panasonic.

Gen3 Prius 10-15 - Redesigned module. Claimed improvements in further reduced internal resistance. I've never been able to measure it. New modules test at 5-6 mΩ. I've seen mild-climate 2004 with 200K miles on it that measure that low.
Gen4 Prius 16+ - redesigned module. Smooth tops. No discernable performance differences. Visually, the module may have higher structural integrity at the plastic welds.

Sometime in the mid to late 20-teens, due to dramatically reduced demand, Panasonic NiMH "D" cells are licensed to a single manufacturer in China.

Since about 2020, all packs purchased as replacements have Gen4 modules.

Toyota makes a SWEET profit on their batteries, and they are vertically integrated. They are STILL making many new models that use the same 6 cell prismatic module. Any rumors that Toyota is discontinuing manufacture or sale of batteries fails every logic test.

[Ecky]

For a short while Honda's replacement G1 packs had "PrimeEarth" branded sticks. I'm curious how and why that ended.

[JSH]

Great battery history lesson - THANKS!