Tire efficiency report

[electric-donut]

I didn't find an active thread for tire efficiency so I thought I would start one. The process is simple. Inspired by the ABRP vehicle power consumption, calculate average power consumption for your vehicle / tire combination. Capture and average power consumption for each direction of a two leg trip. This will minimize affects of elevation change and wind. Travel at least 15 miles at 65 mph on relatively flat road with minimal traffic. Return via the same route and calculate power consumption average for both legs of travel at 65mph. State:

Year / Model - Tire - avg. kwh/mile

 

[electric-donut]

2018 S-100D Continental ContiSportContact 5P F 245/35/21 R 265/35/21 - 290kw/mi

 

[electric-donut]

2018 s100D Pirelli P Zero All Season Plus Elect F+R 245/45/19- 274kw/mi

 

[vcor]

This would be helpful with brand new tires. If the tires are worn, I'd expect poorer results due to higher friction.

 

[mswlogo]

I wonder if this data already exists with Teslafi or something. You really need a lot of data to make any kind of judgement call. Because even the same tires on the same car vary wh/mi driver to driver.

If you are looking for tires one thing I found is trying to find the tire you are interested in, in Europe. Mainly UK because they are also English. Sometimes it exists sometimes not. But they have a rating system for efficiency required by law. I wish they had the same in USA. They also rate noise and wet traction. The noise is external noise though, not cabin noise but they tend to correlate.

Of the several tires I’ve tested Pirelli is often consistently on top for efficiency and noise.

 

[john pane]

Will these be comparable without also controlling for temperature?

 

[beatle]

Worn tires have slightly better (lower) rolling resistance than new tires:

The Relationship Between A Tire's Tread Depth And Rolling Resistance

Tires have to generate a minimum amount of heat and friction and have great heat transfer capability to ensure good rolling resistance.

www.tirereview.com

 

[mswlogo]

Will these be comparable without also controlling for temperature?

I think if you are going to do a comparison type test you want to do the proposed “loop test” with HVAC off. I’ve done that myself with tires, Mudflaps, wheels etc. probably state your tire pressure too.

 

[ucmndd]

This would be helpful with brand new tires. If the tires are worn, I'd expect poorer results due to higher friction.

It’s the opposite. Worn tires have significantly higher efficiency in my experience (on my 6th set).

Cataloging this data without mileage on the tires will not be useful.

 

[electric-donut]

I appreciate the feed back. I appreciate the concept of performing the tests in standardized conditions. Say 72 degrees, a/c off, etc. Living in south Florida, Its going to be difficult to perform the tests with AC off. It was 95 today when I ran with the Pirelli's and 93 the other day when I did the Conti's. If this pans out, I can probably rerun the tests at night when it is cooler later this fall. I think if the a/c is on, as long as the tests are run in more similar conditions, the results will be more repeatable.

The Continental tires are worn down to 5/32 from an original 10/32. The Pirelli's are new, with less than 200 miles on them. I will rerun the test(s) after I return from my road trip establish some "better" numbers.

 

[Giampigua]

In Europe tires are required an “ecolabel” setting the efficiency from A (best) to G (worst)

Please see tire manufacturers European sites.
I just bought Continental Ecocontact 6 which are labelled “A”.
At first impression (one only trip of 300 km) there is a 4% range improvement compared to original tires (Michelin).

 

[electric-donut]

I reran my test on the Pirelli's after I realized I was carrying 150Lbs of sporting equipment and dogs that I didn't have with my Conti test. If I could loose 100 lbs, I could lower the numbers a bit more!

I also want to note I am running on autopilot while performing test. I have suspension set to low.

2018 s100D Pirelli P Zero All Season Plus Elect F+R 245/45/19- 269kw/mi

 

[cmarshack]

You are also leaving out the most important data point, Tire Pressure.

 

[electric-donut]

Not wanting to reinvent the wheel, I suggest going with cold tire pressure as stated on the door jamb.

 

[bradtem]

Yeah, this is going to vary based on your driving style, how fast you drive, pressure and many other factors. Other than a well defined test, one thing most of us can do is compare one set of tires to another with the same car and drivers.

So I can report: 235/45R-18 Vredestein Quatrac Pro - 252 wh/mile over first 7,000 miles vs 245 wh/mile over 26,000 miles on the original Michelin MXM4s. So the Vredesteins are 2.8% less efficient, which is tolerable. They seem to perform well and were vastly less expensive. When they were new they had a hum on highway 280 but it went away fairly soon.

 

[beatle]

So I can report: 235/45R-18 Vredestein Quatrac Pro - 252 wh/mile over first 7,000 miles vs 245 wh/mile over 26,000 miles on the original Michelin MXM4s.

Note that this is the Model S forum.

 

[bradtem]

Note that this is the Model S forum.

Apologies, this is a model 3 report. However, it can still be used to compare the brands so I hope it remains of value.

 

[SignatureSales]

Model S Plaid - Michelin PS4S 265/35/21 & 325/30/21 @ 45PSI. 65-70 mph round trip, AC 72f fan speed 4.

320 wh/mi

 

[airborne spoon]

I have Falken Azenis on my car and I made the same 30 mile trip 4 times (2 each direction) (clocking a 22 mile section as the test site) at 65 mph and the average is 600 wh/mi but i was also towing my trailer because i wanted to see what its number was to better plan trips with ABRP. And i gotta say after putting in the 600 to ABRP and plotting the same trip the percentages were spot on for what they were when i arrived to each spot.

I tried to take the same trip the next day with no load but after one direction i got a nail in my tire so the results are inconclusive till i get a new tire on there. But the one way was 280 wh/mi.