Snow Tires cost 10% of efficiency

[klezmerman]

I bought my snow tires -- Bridgestone Blizzak WS90 -- for my SR+ on December 9 and noticed an immediate decrease in range. I finally have enough data to quantify this and came up with about a 10% increase in Wh/Mile. I looked at all trips greater than 5 miles and with an ambient outside temperature between 30-40 degrees. I limited the temperature range to control for battery efficiency and heater usage.

Prior to the snow tires I was getting 285 wh/mi and after the snows I get 311 wh/mile.

A contributing factor might be that I bought the tires mounted so I don't have the standard Aero wheel covers.

On the plus side, the snow tires work really well and are a considerable improvement over the stock tires.

By the way, I get my data from a FleetCarma device, plugged into the OBDC port, that my electric company provides here in Rhode Island to track the car's usage so that they can understand BEVs better. A side benefit is an extremely detailed spreadsheet that documents every trip in the car.

Hope this helps someone if they are deciding whether to get snow tires.

 

[Fresnel]

I bought my snow tires -- Bridgestone Blizzak WS90 -- for my SR+ on December 9 and noticed an immediate decrease in range. I finally have enough data to quantify this and came up with about a 10% increase in Wh/Mile. I looked at all trips greater than 5 miles and with an ambient outside temperature between 30-40 degrees. I limited the temperature range to control for battery efficiency and heater usage.

Prior to the snow tires I was getting 285 wh/mi and after the snows I get 311 wh/mile.

A contributing factor might be that I bought the tires mounted so I don't have the standard Aero wheel covers.

On the plus side, the snow tires work really well and are a considerable improvement over the stock tires.

By the way, I get my data from a FleetCarma device, plugged into the OBDC port, that my electric company provides here in Rhode Island to track the car's usage so that they can understand BEVs better. A side benefit is an extremely detailed spreadsheet that documents every trip in the car.

Hope this helps someone if they are deciding whether to get snow tires.

I think they say Aero wheel covers add 7% so.. that's probably a big contributing factor to your range loss.

 

[afadeev]

I bought my snow tires -- Bridgestone Blizzak WS90 -- for my SR+ on December 9 and noticed an immediate decrease in range.

I have the opposite experience.
My baseline are Michelin 4S summer tires, and my efficiently increased by ~5% once I switched to winter tires (X-Ice) in late October (for roughly the same ambient temps, the same commute rout).
I do have Blizzak WS*0 tires on my other cars, and notice efficiency gains from riding on winter tires from ICE cars as well.

Once the temps dropped below 50F, Model 3 efficiency started decreasing, but that has nothing to do with the tires.

Prior to the snow tires I was getting 285 wh/mi and after the snows I get 311 wh/mile.

I had roughly the same summer tire consumption (286 Wh/mi). Then it dipped into 270 range for a few weeks of balmy ambient temps on X-Ice tires. However, that data sample was way too short to be statistically significant.
Once temps started dipping below freezing in December, I've been averaging consumption in 350-410 Wh/mi territory (the colder, the higher).

On the plus side, the snow tires work really well and are a considerable improvement over the stock tires.

Definitely!

I would not dare to drive on winter NE roads on anything other than dedicated winter tires.
FWD, RWD, or AWD - the same strong preferences.

a

 

[jmaddr]

That's not a bad drop at all. Certainly the aero has something to do with it. You didn't mention which wheels you purchased, or the tire/wheel weight difference between the two, or the tire pressure during each of these runs. All these things could have something to do with it other than the tread but I'd say that's not terrible or concerning at all, especially considering the safety of winter tires.

 

[TomB985]

I noticed very similar, but blame my aftermarket wheels a lot more than I do the tires. Definitely a selling point of the factory Aero winter tire package, but for the $700 difference it wasn’t worth it for me.

 

[nvx1977]

I went from stock all seasons with aero covers to Tesla's winter sottozeros with aero covers. I see very little difference in efficiency due to the tires. I have 2 cold seasons worth of data from the all-seasons to compare with this year's cold season on the winter tires.

 

[ZOMGVTEK]

I didn't really notice any major difference in efficiency going to Nokian Hakkapeliitta 9's. It appears to be within a few percent. They are definitely very loud...

 

[CharleyBC]

We're currently visiting a small city in OR where I estimate 20% of the passing cars are on snow tires, based on the sound. Given all the acoustic energy clearly being spent, it's easy to believe they'd be less efficient. But it's like so many things in life, right? You trade off an advantage (secure driving in snow) for a disadvantage (efficiency impact).

 

[TomB985]

We're currently visiting a small city in OR where I estimate 20% of the passing cars are on snow tires, based on the sound. Given all the acoustic energy clearly being spent, it's easy to believe they'd be less efficient. But it's like so many things in life, right? You trade off an advantage (secure driving in snow) for a disadvantage (efficiency impact).

Sounds like you’re around studded tires.

Not all snow tires have studs, and mine haven’t made a noticeable difference in road noise compared with the factory Michelin’s.

 

[afadeev]

We're currently visiting a small city in OR where I estimate 20% of the passing cars are on snow tires, based on the sound. Given all the acoustic energy clearly being spent, it's easy to believe they'd be less efficient.

Snow tires do NOT sound any different then regular tires.
The difference in traction is arrived from custom rubber compounds (which stay soft and pliable in sub-freezing temps) and additional sipes in the tread, on the tread blocks.

If the tires sound way louder, it is either because they are old-fashioned truck & mud tires, or have metal studs on them.

But it's like so many things in life, right? You trade off an advantage (secure driving in snow) for a disadvantage (efficiency impact).

False conclusion based on unverified data.

 

[neurocutie]

presumably you actually get snow, ice and rain... so how are you accounting for the loss of efficiency due to loss of friction, traction, road conditions, etc?

btw on my BMW (328xi) I consistently observe a loss of about 10% of MPG from summer/fall to winter (including snow and < 20deg weather).

 

[neurocutie]

I bought my snow tires -- Bridgestone Blizzak WS90 -- for my SR+ on December 9 and noticed an immediate decrease in range. I finally have enough data to quantify this and came up with about a 10% increase in Wh/Mile. I looked at all trips greater than 5 miles and with an ambient outside temperature between 30-40 degrees. I limited the temperature range to control for battery efficiency and heater usage.

presumably you actually get snow, ice and rain... so how are you accounting for the loss of efficiency due to loss of friction, traction, road conditions, etc?

btw on my BMW (328xi) I consistently observe a loss of about 10% of MPG from summer/fall to winter (including snow and < 20deg weather).

 

[TomB985]

Snow tires do NOT sound any different then regular tires.
The difference in traction is arrived from custom rubber compounds (which stay soft and pliable in sub-freezing temps) and additional sipes in the tread, on the tread blocks.

If the tires sound way louder, it is either because they are old-fashioned truck & mud tires, or have metal studs on them.




False conclusion based on unverified data.

U mad, bro?

There are a lot better ways of putting things unless you're trying to start a fight.

 

[5_+JqckQttqck]

Wet roads = less friction. Therefore, more slip and use more energy to get to the same place.

 

[19White3]

I haven't experienced much, if any, loss with my Dunlop Wintermaxx tires. I put them on the stock aero wheels and have taken a few 200+ mile trips. I definitely drive less sporty with the winter tires on compared to the stock tires, so that likely helps.

 

[coconutboy84]

Snow tires do NOT sound any different then regular tires.
The difference in traction is arrived from custom rubber compounds (which stay soft and pliable in sub-freezing temps) and additional sipes in the tread, on the tread blocks.

If the tires sound way louder, it is either because they are old-fashioned truck & mud tires, or have metal studs on them.




False conclusion based on unverified data.

your statements are actually the false ones. Snows do sound different, this is a fact.

 

[CrayZ1]

Note that cold roads/air increases rolling resistance of tires. Cold air also slightly harms aero resistance. Water on roads really reduces range. You see that water spray coming up from tires on the highway? That is lifting water and accelerating it. You can feel it when you cross a small wet strip in a dry road.

 

[camalaio]

I applaud your attempts to control variables, well done. Others seem to be telling you to control for the very things you already have.

I agree it's probably a lot to do with the lack of Aero covers (as long as the trips you counted are mostly highway travel), which puts a few percent left towards winter tire inefficiency. Sounds about right.

I have the opposite experience.
My baseline are Michelin 4S summer tires, and my efficiently increased by ~5% once I switched to winter tires (X-Ice) in late October (for roughly the same ambient temps, the same commute rout).

FWIW, X-Ice in my experience tends to be some odd outlier. They were always quieter than my all seasons. Always more efficient as well. But also in my experience they were the worst tire for wet snow and slush (which we get a lot) so I no longer use them. They're a bit more like a "Performance" Winter tire in my opinion.

 

[preilly44]

I went from 20" summer tires to (non aero) 18" winter tires my efficiency increased from 287 (summers) to 267 (winter tires).