Speed limiter

Weber State auto dissects the Prius transaxles. They got weaker and faster motors each generation. The 17000 rpm is to use more gear reduction to get more power from a weaker motor. It’s like going 85 mph in low gear in a gas car more or less. So you are stuck with the speed limiter. Hope to see his tear down of the gen 5 transaxle.

 

All Priuses have been subject to MG2 speed limits - there's always been definite design target/limit for the motor and inverter, even before the current 17000rpm version.

From some geeky notes I made in the past, I believe the limits were as follows, and I've converted to speed based on standard wheel size.

G1: 6000rpm = 169km/h = 105mph. Speed limiter set to 160km/h = 99mph.
G2: 6500rpm = 185km/h = 115mph. Speed limiter set to 170km/h = 106mph
G3: 13500rpm = 185km/h = 115mph. Speed limiter set to 180km/h = 112mph
G4 HEV: 17000rpm = 187km/h = 116mph. Speed limiter set to 180km/h = 112mph
G4 PHEV: 17000rpm = 165km/h = 103mph. Speed limiter set to 162km/h = 101mph
G5 1.8 HEV: 17000rpm = 185km/h = 115mph. Speed limiter set to 180km/h = 112mph
G5 2.0 HEV: 17000rpm = 193km/h = 120mph. Speed limiter set to 180km/h = 112mph
G5 PHEV: 17000rpm = 182km/h = 113mph. Speed limiter set to 177km/h = 110mph.

G3 and later HEVs can reach the 180km/h limit that Toyota applies across models without overspeeding MG2, so the speed limiter is set there.

G1, G2 and PHEVs get a lower limit because of MG2.

 

Coming back to the autobahns without speed limits, it looks like they are a true nightmare. It seems to be a marketing ploy to promote the German car industry.

Autobahn safety—Wikipedia

Here in the LA area, even though it is illegal, there are a lot of people who do 180 and higher.

 

AI Factcheck:

This statement is not supported by the data in the article. The article presents a nuanced view of autobahn safety:

• Autobahns carried 31% of motorized road traffic while accounting for only 11% of Germany's traffic deaths in 2014.
• The fatality rate on autobahns (1.6 deaths per billion travel-kilometers) was lower than on urban streets (4.6) and rural roads (6.5).
• While unlimited sections accounted for 71% of fatalities, they also make up 70% of the network, suggesting proportionality rather than excess danger.

Calling autobahns a "true nightmare" is an exaggeration not supported by the statistics.

If it is then it works pretty well!

 

More quoting the autobahn article.
“Penalties for tailgating were increased in May 2006 to a maximum of €375 (now €400[119]) and three months' license suspension:[120] "drivers must keep a distance in metres that is equal to half their speed. For example, a driver going 100 km/h on the autobahn must keep a distance of at least 50 metres (165 feet)". The penalty increase followed uproar after an infamous fatal crash on Autobahn 5 in 2003.[121”

 

I understand they are also very strict about staying right except to pass.

Eh, I had my gen2 up to 90mph(145kmh) on an Interstate with a 70mph limit. There are freeways in some states with 85mph limits. I suspect many cars are being pushed to what are considered excessive speeds by the US Toyota manual.

Besides, I think your synthetic oil there is truly group IV and V synthetic oils, and not just a marketing term like here.

 

Heck, I just spent a couple hours yesterday cruising at 85mph/135kmh. Speed limit was 80. (does baaaaad things to mpg - lol)

 

He didn't drive to München after all.

By the way, it is not really true that the speed limits are much higher in the Europe than in the US. The highest speed limits are 81–87 mph; so, they are not any different than states like Texas here. Germany is an exception for having no speed limits in the rural sections of autobahns (there are in the urban sections). Even in the rural sections, the “recommended” speed limit is 81 mph.

And, unlike in Germany, eighteen-wheelers in Texas do 90 mph on the interstates.

 

There is a huge difference between 180 km/h (112 mph) and 85–90 mph. When considering speed, you should look at the square of the speed, as both the braking distance and centripetal forces are proportional to the square of the speed. Therefore, 112 mph is 55% faster than 90 mph—not 24%—in terms of maneuverability. Likewise, it is 74% faster than 85 mph in that sense. Moreover, the destructive energy (kinetic energy) of the vehicle is also proportional to the square of the speed if you get into an accident. Therefore, you are not only greatly increasing the chances of an accident by speeding but also greatly increasing the chances of getting hurt when it happens.

 

AI?? Come one, AI can hardly tell an apple from an orange in its current state, let alone perform any analysis that requires actual intelligence.

 

Yes, I know.

I also know there are many, many places in the plains states where the roads are in good condition, there are no visual obstructions near the roads, they are straight as an arrow, the grade allows you to see for 2-3 miles in front of you, and it's perfectly safe to get up to 120mph+ for short periods just to see how the car behaves at those speeds. While it's highly unlikely a person will ever need to go that fast, it's still good to know what to expect in an emergency.

Personal examples:
My family owned an '81 MB 300D. Not exactly the fastest car in the world, but it could still get up to 80-85(in an era where the top US speed limits were 65). I took that car to its top speed several times because I discovered the handling actually improved above 65(probably because the chassis was designed for the Autobahn and was also used in cars with much more powerful engines).

Many years later, my parents owned an early-90's Chrysler NY 5th Ave. I took that car up to maybe 80-85 ONE time. Around that speed, the car's handling turned into a nightmare. Floaty, imprecise; it felt like the car might want to change directions on its own at any time and head for the ditch. I knew never to try high speeds with that car, even in an emergency.

An extension of this was growing up with RWD vehicles in a region that gets significant snow. Until my late 20s/early 30s, I would go out after midnight on the first good snow of the season and find an empty parking lot with no/minimal light poles. Then I would deliberately lose control while accelerating, turning, and stopping. It refreshed my memory of how long it would take for me to stop, how much acceleration I could use before the wheels started to spin, and at what speeds would I lose the ability to safely turn. After 30-45min of practice, I would be good for the rest of the winter.

If you don't (safely) test for the edge conditions in semi-controlled environments, how will you ever know what to expect if you encounter a real emergency?

 

It’s the speeders bullying others in traffic and not just speeding out on an empty road that is so wrong.

 

Back in the day when I tuned Subaru WRX/STi's, you could modify a bunch of vehicle settings but the 156mph was one thing you could not remove the limit from. Some things are hard coded.

115mph is plenty fast enough, you'll over spin one of the MG's... keep in mind how fast it's already spinning at 100mph.

 

Like the GR Corolla that Toyota (of America) said burned down because it was driven in excess of 85mph?

I've wasted some time online looking for people modifying this generation of Prius not for better top speed but for greater electric operation or more electric torque. I thought there must be someone who had incorporated Sienna drive components and or/retuned the ecu to bias battery use over longevity, but I've not seen anything like that.

 

know how much work it takes? to safely modify a toyota? honda? hybrid system? Sure it's been done, not on any Gen 4 or 5 that I"ve seen either. Know how long @jacktheripper has been testing his modification and which makes / models are supported? Pleas don't ask me to make a guess, it will more than likely be way off.