# tire efficiency



## SR22pilot (Aug 16, 2018)

Frully said:


> Greetings, and welcome.
> 
> Agreed with @GDN on practically all points.
> 
> ...


Have you looked at the Aero's with the covers removed?

To see range impacts of various combinations I have found this sites data pretty good: https://teslike.com/range/


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## mswlogo (Oct 8, 2018)

SR22pilot said:


> Have you looked at the Aero's with the covers removed?
> 
> To see range impacts of various combinations I have found this sites data pretty good: https://teslike.com/range/


Ignore that silly chart. Put what ever wheels you like. Then choose a tire based on traction vs efficiency and longevity. You tire selection will be more limited on 20" rims though.

The differences are due to tire compound, not the rim size. And are dwarfed by how you drive and weather.


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## garsh (Apr 4, 2016)

mswlogo said:


> Ignore that silly chart. Put what ever wheels you like. Then choose a tire based on traction vs _*efficiency*_ and longevity.


Unfortunately, "silly charts" like this are needed to actually understand the differences in efficiency of wheel/tire combos. It's just more data to allow people to make an informed decision.


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## mswlogo (Oct 8, 2018)

garsh said:


> Unfortunately, "silly charts" like this are needed to actually understand the differences in efficiency of wheel/tire combos. It's just more data to allow people to make an informed decision.


It's a very misleading chart and people make decisions on it for the wrong reasons.

I switched from Aero's with covers to 19" OEM and should have lost 7% according to that "silly chart", I've lost 0%. Why?Because I didn't use the OEM 19" tire.

If you want range? Change your tires. Don't look at the chart and change your rims.


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## SR22pilot (Aug 16, 2018)

mswlogo said:


> Ignore that silly chart. Put what ever wheels you like. Then choose a tire based on traction vs efficiency and longevity. You tire selection will be more limited on 20" rims though.
> 
> The differences are due to tire compound, not the rim size. And are dwarfed by how you drive and weather.


The rim sizes listed in the chart are just a quick way to reference the tire/rim combination. I agree the rim makes relatively small difference. The Aero cover effect is clearly illustrated. It shows only a small difference between the 19" factory setup and the 20" setup on the Performance. You do gain a lot by going to the low rolling resistance tires on the 18" combined with the aero covers.

Weather and how you drive do affect things. However, I see a noticeable difference between my two cars even when one is following the other. I don't have definitive number but I would guess the difference is around 50 miles. For that reason we always take the RWD car on long trips.


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## mswlogo (Oct 8, 2018)

SR22pilot said:


> The rim sizes listed in the chart are just a quick way to reference the tire/rim combination. I agree the rim makes relatively small difference. The Aero cover effect is clearly illustrated. It shows only a small difference between the 19" factory setup and the 20" setup on the Performance. You do gain a lot by going to the low rolling resistance tires on the 18" combined with the aero covers.
> 
> Weather and how you drive do affect things. However, I see a noticeable difference between my two cars even when one is following the other. I don't have definitive number but I would guess the difference is around 50 miles. For that reason we always take the RWD car on long trips.


Do you have the same rubber on both cars?


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## garsh (Apr 4, 2016)

mswlogo said:


> It's a very misleading chart and people make decisions on it for the wrong reasons.


That could be. There's not a lot of explanation included with the chart.


> I switched from Aero's with covers to 19" OEM and should have lost 7% according to that "silly chart", I've lost 0%. Why?Because I didn't use the OEM 19" tire.


Gotcha.

Yes, my understanding was that Troy was trying to capture the efficiency differences of completely OEM cars with that chart. You are correct - it should not be relied upon once you've switch wheels or tires.


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## Dr. J (Sep 1, 2017)

mswlogo said:


> [1] It's a very misleading chart and [2] people make decisions on it for the wrong reasons.


1. No, it's not. It's based on copious research and calculation, most of which is explained in this thread: https://teslaownersonline.com/threads/tesla-model-s-x-3-range-at-55-60-65-70-75-80-mph.5496/ . 
2. Where is the evidence people are making decisions on it for the wrong reasons? And I guess you are the judge of which reasons are right and wrong, for other people?


garsh said:


> That could be. There's not a lot of explanation included with the chart.


See thread above for explanations.


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## SR22pilot (Aug 16, 2018)

mswlogo said:


> Do you have the same rubber on both cars?


No. Both cars have the factory tires that come with the rims. The 18" Aero rims come with EV tires (Michelin Primacy MXM4, 235/45-18, 98W) designed for very low rolling resistance. The 19" rims come with tires designed for more balanced all season performance (Continental ProContact RX, 235/40-19, 96W). The 20" comes with Michelin Pilot Sport 4S, 235/35-20 92Y. I think I have those correct.


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## mswlogo (Oct 8, 2018)

Dr. J said:


> 1. No, it's not. It's based on copious research and calculation, most of which is explained in this thread: https://teslaownersonline.com/threads/tesla-model-s-x-3-range-at-55-60-65-70-75-80-mph.5496/ .
> 2. Where is the evidence people are making decisions on it for the wrong reasons? And I guess you are the judge of which reasons are right and wrong, for other people?
> 
> See thread above for explanations.


I did. I used that stupid chart to decide to buy 2nd set of Aeros last fall. Finally decided the heck with it, I'm buying 19 OEM's expecting to eat 7%. I didn't. And if I knew what I knew today I would have bought 19" last fall.

It's always Aero's, Aero's, Aero's. People order the Aero's because they think that's the only way they can get the range. When they really want the 19". We'll they can. Just get rid of the 19" OEM tires if you want range.

It's constantly brought up that "Aero" is the only way to get good range. Then they link that chart as "proof".

It's the rubber, and you can put more efficient rubber on any OEM rim.

If you put the same tire on all 3 wheels you'd barely notice any difference. And if people knew that they would choose differently.

In fact the guy that bought my Aero's was getting rid of his 19" OEM for max efficiency. All he had to do was get more efficient tires. You can get better 19" tires than Primacy 18" that even make up for the Aero covers.


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## GDN (Oct 30, 2017)

mswlogo said:


> It's a very misleading chart and people make decisions on it for the wrong reasons.
> 
> I switched from Aero's with covers to 19" OEM and should have lost 7% according to that "silly chart", I've lost 0%. Why?Because I didn't use the OEM 19" tire.
> 
> If you want range? Change your tires. Don't look at the chart and change your rims.


Wow - that chart really bothers you doesn't it? There is a lot of good guidance in that chart and offers very good guidance in a perfect world. The chart may not be perfect, but for someone that is new to the EV and battery sizes and tires. It is very good guidance and demonstration of differences.

There is no need to trash it, if you don't like it move on.


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## mswlogo (Oct 8, 2018)

GDN said:


> Wow - that chart really bothers you doesn't it? There is a lot good guidance in that chart and offers very good guidance in a perfect world. The chart may not be perfect, but for someone that is new to the EV and battery sizes and tires. It is very good guidance and demonstration of differences.
> 
> There is no need to trash it, if you don't like it move on.


If I see a discussion over someone struggling between 18" Aero's, 19" or 20" (which is quite often) and someone responds, if you want maximum range get the ugly Aero's and here is the chart to prove it (which is misleading advice) I have every right to say, ignore the chart and consider selling the OEM tires and get high efficiency tires and have the best of both.


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## garsh (Apr 4, 2016)

mswlogo said:


> If I see a discussion over someone struggling between 18" Aero's, 19" or 20" (which is quite often) and someone responds, if you want maximum range get the ugly Aero's and here is the chart to prove it (which is misleading advice) I have every right to say, ignore the chart and consider selling the OEM tires and get high efficiency tires and have the best of both.


It's hard to trust a random person on the internet who says to ignore a carefully produced chart and calls it silly without explaining that they are actually complaining about people using the chart incorrectly.


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## SR22pilot (Aug 16, 2018)

mswlogo said:


> If I see a discussion over someone struggling between 18" Aero's, 19" or 20" (which is quite often) and someone responds, if you want maximum range get the ugly Aero's and here is the chart to prove it (which is misleading advice) I have every right to say, ignore the chart and consider selling the OEM tires and get high efficiency tires and have the best of both.


There are many different aftermarket rims and aftermarket tires. Imagine the chart if you tried to include all combinations. Most people are looking at just buying the car and what is available when they order. Feel free to build a chart that shows the range differences of different tire combinations and I will be happy to also reference it. Right now I just know that my RWD gets about 50 miles greater range (real world use) than my AWD on 19". That is due to several factors (RWD vs. AWD, tires, Aero rims). The chart agrees with what I see.

You also mention the ugly Aeros. I have them on my RWD because it is really my partner's car and she prefers the look and didn't want to spend the extra money. She also thought they better matched the black interior that she got. As they say, beauty is in the eye of the beholder. I will say that if you take the Aero covers off, the rims look much like the rims that came on her Mustang (Pony Package) that she used to have. I happen to prefer brighter looking rims so I got the 19's. Besides, I have the white interior so they match better. Other than the difference in color, I'm not sure I would consider the 19's that much better looking than the Aeros minus the covers.


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## mswlogo (Oct 8, 2018)

SR22pilot said:


> There are many different aftermarket rims and aftermarket tires. Imagine the chart if you tried to include all combinations. Most people are looking at just buying the car and what is available when they order. Feel free to build a chart that shows the range differences of different tire combinations and I will be happy to also reference it. Right now I just know that my RWD gets about 50 miles greater range (real world use) than my AWD on 19". That is due to several factors (RWD vs. AWD, tires, Aero rims). The chart agrees with what I see.
> 
> You also mention the ugly Aeros. I have them on my RWD because it is really my partner's car and she prefers the look and didn't want to spend the extra money. She also thought they better matched the black interior that she got. As they say, beauty is in the eye of the beholder. I will say that if you take the Aero covers off, the rims look much like the rims that came on her Mustang (Pony Package) that she used to have. I happen to prefer brighter looking rims so I got the 19's. Besides, I have the white interior so they match better. Other than the difference in color, I'm not sure I would consider the 19's that much better looking than the Aeros minus the covers.


I agree it would be hard to list every combo.

It's not a huge data point but efficiency seems to correlate with tread wear rating. The higher the more efficient.

From memory

OEM 18" are 500
OEM 19" are 400
OEM 20" are 230

The 19" I got are 700

That's much closer to what's happening than what the chart portray's.


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## mswlogo (Oct 8, 2018)

garsh said:


> It's hard to trust a random person on the internet who says to ignore a carefully produced chart and calls it silly without explaining that they are actually complaining about people using the chart incorrectly.


So I'm not allowed to speak my opinion? I think folks can decide for themselves without your trying to find clever tactics discredit mine. I've also seen a few reports confirming what I've observed.

It's hard to trust folks that only know how to post a link versus someone that just spent $2800 to swap and carefully tested to find out how much loss he was gonna get only to find out it 0%. In fact I think it's doing a little better than Aero's. I chose the tires I did because I was very concerned about road noise. I never expected them to come close to Aero's.

I do the same 300 mile trip every few weekends. When I first got the car in late September I got 242 wh/mi no HVAC I've been logging it by hand. Just finished same trip just now. Ran A/C 68F (82F outside) almost the whole way. 237 wh/mi. Same speed 65 mph. Same tire pressure (42 psi cold). AWD. Also two adults, 2 dogs and full trunk (probably an extra 250-300 lbs).

I think as it gets hotter the tire pressures goes up in the tires and makes up for the A/C.


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## Dr. J (Sep 1, 2017)

Here's another relevant source: https://forum.abetterrouteplanner.c...-consumption-real-driving-data-from-233-cars/. It's a real world comparison of RWD vs. Performance, but the P is probably a useful substitute for AWD. Graphs in imperial units are at the bottom of the page. No distinction between wheel sizes or tires.


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## Tchris (Nov 22, 2017)

mswlogo said:


> I agree it would be hard to list every combo.
> 
> It's not a huge data point but efficiency seems to correlate with tread wear rating. The higher the more efficient.
> 
> ...


I may have missed it somewhere in this thread, but which 19" tires, specifically, did you end up buying?


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## GDN (Oct 30, 2017)

mswlogo said:


> I agree it would be hard to list every combo.
> 
> It's not a huge data point but efficiency seems to correlate with tread wear rating. The higher the more efficient.
> 
> ...


This is good to know, but the first I'm hearing and learning from it. I can google more, but what else should we know about these numbers? Tires for EV's are still a relatively new thing in the grand scheme of tire history. This is a huge step in the right direction, providing some real numbers or proof of what you are saying. Everyone on this forum wants to learn and share information, that is what we are all about. Attacking others and real math with just trying to discredit doesn't get us anywhere. Do you have enough miles on these tires to give us some really good numbers? What kind of wh/mi are you getting to show that they are superior tires?


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## Feathermerchant (Sep 17, 2018)

Rims and wheels are two different things. The rim is a part of the wheel. You can buy a wheel you cannot buy a rim.

I have the performance model that came with 20" wheels and PS4S tires. I did not like the lack of sidewall and heavy (30 lb) wheels so I replaced the with 18" forged (18 lb 6oz) wheels and Primacy MXMV tires. 
It used to ba a challenge to stay under 300 Wh/mi. Now I'm more like 260 on the highway. Keep in mind the 75 mph limits we have here in Tx meaning people drive 80 or so.

Got a kick out of "A/C at 68 deg" above. Mine is usually set at 77. It has already been 98 here. And there is more sun.


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## Hank101 (Jun 5, 2019)

Tchris said:


> I may have missed it somewhere in this thread, but which 19" tires, specifically, did you end up buying?


Looking for the same info... Which tire?


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## Bdehaan (Jun 7, 2019)

How does one shop for tires based on the efficiency? What number or rating when shopping for tires determines what their efficiency would be? I also hate to ask this so soon, but being from Canada, and already having to take a huge range hit for temperature, how should I shop for a winter tire that offer me the best efficiency? I am about to pick up a AWD-LR, so for summer I am not nearly as concerned about a hit to range but when it comes to -20'Celcius....that may be a different story?


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