UTV's and ATV's general discussion.

[DK35vince]

Yeah that doesn't make much sense at all. I didn't have Polaris on my list and sounds like it'll never make it on the list haha!

Not all Polaris models do that, It depends on the model.
I have a Polaris RZR 900s, and it has engine braking all the way to a stop.
It does not free wheel at slower speeds.

 

[nforktractor]

I have a 2018 Polaris XP1000, it has engine braking, pretty stout, you take your foot off the throttle and slows right down, even going down a hill.

 

[deserteagle71]

I have a 2018 Polaris XP1000, it has engine braking, pretty stout, you take your foot off the throttle and slows right down, even going down a hill.

My understanding is that it is an option on most of the Polaris models. The clutch assembly that allows engine braking is available from Polaris:

My question is...why is this an option when all the other manufacturers have it as standard equipment? Why would anyone want a machine that provides no engine braking going down a steep hill?

 

[Grumpycat]

Its exponential not linear it depends on what temperture we are talking about, and the specific battery but yes cab and battery heating are also a major component. At 0 degree C its marginal but -20 degree Celsius the lost is substantial.

its very technical but that's the study, it highlights that at -20°C, lithium-ion batteries experience a significant reduction in efficiency due to decreased ionic conductivity and slower electrochemical reactions. Capacity can drop as much as as 50% of the rated value depending on the specific battery design and materials.

Again, what do you know of the cited vehicle?

It doesn't have a heated cab.

We don't know if it has any thermal battery management. We do know when used lithium chemistry batteries self-heat. We don't know what battery chemistry that vehicle uses.

Is not as if diesel is a delight in cold temperatures. But somehow one makes do and overlooks this issue.

I'm just saying, "Don't tell us what you don't know. Just because all your friends say it doesn't make it true."

 

[Grumpycat]

Come on grumpy, batteries loose capacity when they are cold are you denying that?

• Lithium-Ion Batteries:
  • Lithium-ion batteries, commonly used in smartphones, laptops, and electric vehicles, can lose 20-40% of their capacity at freezing temperatures (0°C or 32°F).
  • At very low temperatures (-20°C or -4°F), the capacity loss can be even greater.
• Lead-Acid Batteries:
  • Lead-acid batteries, often used in cars, lose about 20% of their capacity at 32°F (0°C) and up to 50% at -22°F (-30°C).

Wonderful! Generic information from an uncited source!

ICE loses range too. At 40°F my Subaru got 26 MPG at 70 MPH. Or 32 MPG at 70°F. Miles Divided By Gallons, not the number shown on the instrument panel.

Now what battery is in the cited vehicle?

And based on the data you copy/pasted are you going to abandon your ICE vehicles in the cold because the lead-acid starter battery's capacity diminishes? Clearly it is unusable because capacity is no longer 100%.

Or, maybe it is just something you live with?

 

[Code54]

Some of the Polaris models used to freewheel below a certain speed so the “trick” was to touch the gas to keep the RPMs up and keep the engine brake engaged.

 

[Eagle1]

Some of the Polaris models used to freewheel below a certain speed so the “trick” was to touch the gas to keep the RPMs up and keep the engine brake engaged.

Our Brute Force is like that you have to keep the engine RPM above 1500 to have braking. If the centrifugal clutch disengages you free wheel down the hill

 

[Too many Kubotas]

ICE loses range too. At 40°F my Subaru got 26 MPG at 70 MPH. Or 32 MPG at 70°F. Miles Divided By Gallons, not the number shown on the instrument panel.

My vehicles also lose a few mpg in the winter, but I strongly suspect that it's because the fluids just don't flow as well when it's zero degrees. After 20 miles or so the mileage tends to increase as things warm up.

The engine itself? I don't think the ambient temp can be too cool for a gas engine. They run better with cold air going down the intake tract. Otherwise there wouldn't be so many so-called cold air intakes for sale (many are worse than OE, but that's a different story).

Also, nobody would use charge air coolers (usually referred to as intercoolers, which they normally are not) if it didn't help to have lower intake temps.

 

[Grumpycat]

My vehicles also lose a few mpg in the winter, but I strongly suspect that it's because the fluids just don't flow as well when it's zero degrees. After 20 miles or so the mileage tends to increase as things warm up.

The engine itself? I don't think the ambient temp can be too cool for a gas engine. They run better with cold air going down the intake tract. Otherwise there wouldn't be so many so-called cold air intakes for sale (many are worse than OE, but that's a different story).

Also, nobody would use charge air coolers (usually referred to as intercoolers, which they normally are not) if it didn't help to have lower intake temps.

Cold air intakes get more air mass in the same space at the same time. More oxygen for combustion, more opportunity to make power.

Intercoolers are used on turbocharged or supercharged engines because the compressed air rises in temperature. Cool it a bit and once again one can get more air mass in the combustion chamber.

There once was concern about carburetor air intake falling below 100°F and creating an icing condition as it accelerates and cools going through the throat of the carburetor. Have known several "geniuses" who removed the little hose between exhaust manifold and air filter intake horn who then had unexplained problems on longer trips. Unexplained until one looked down the carburetor throat.

Carburetor icing is a major concern for piston powered aircraft.

But once again back to my original theme, all this is theoretical. In engineering we guess these things this way, then actually try it. Doesn't always work the way we expected. I never expected the Subaru to reliably get so much poorer mileage in cool weather. No other vehicle I have owned has been so extreme. But this is actual real world data and not 29 year old living in mother's basement surfing the internet.

 

[Rockbadchild]

Wonderful! Generic information from an uncited source!

ICE loses range too. At 40°F my Subaru got 26 MPG at 70 MPH. Or 32 MPG at 70°F. Miles Divided By Gallons, not the number shown on the instrument panel.

Now what battery is in the cited vehicle?

And based on the data you copy/pasted are you going to abandon your ICE vehicles in the cold because the lead-acid starter battery's capacity diminishes? Clearly it is unusable because capacity is no longer 100%.

Or, maybe it is just something you live with?

nice to see you admit the facts