I know the adults are all concerned about the safety but...
Are LRRs better for burnout videos?
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Low Rolling Resistance (LRR) tires
- Thread starter joshuaeven
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- Driving Dynamics Model S
Are LRRs better for burnout videos?
artsci
Sponsor
Thanks for the informative reply. Your experiment with wheel covers is interesting to say the least.
Of course, ss I'm going to have to buy tires for the 19" wheels, they might as well be LLR's even if the benefit it terms of range is modest. Every mile counts!
LRR - Are "LRR tires" and "winter tires" incompatible concepts? I suspect so, but I'll ask anyway...
I've been "casually considering" a set of 19" with winter tires, and am curious if LRR is an option on that so that the tires could serve dual purpose as "efficient for road tripping" and "safe in winter" wheels. I suspect not, but thought I'd ask.
I've been "casually considering" a set of 19" with winter tires, and am curious if LRR is an option on that so that the tires could serve dual purpose as "efficient for road tripping" and "safe in winter" wheels. I suspect not, but thought I'd ask.
artsci
Sponsor
The 4th one here?
Tire Search Results
Click "Show ONLY LRR Tires (4)" in the bottom left after navigating to the link.
Not in the least. Nokia Hakkepeliitta R tires are very low rolling resistance and they are one of the best winter tires you can buy. The WR-g2 is no slouch in the RR department either (I got up to 70 mpg over a tank full on my Prius with WR-g2), but unfortunately doesn't come in Model S size.
artsci
Sponsor
I don't think he was saying that's our only option. He was just confirming that I found the one he mentioned.
artsci
Sponsor
That's correct. 4th one down on the Tirerack list you posted. I was not suggesting that the Michelins were "it" as far as LRR tires go. In fact, one of the major problems with LRR's is that there is no standardized rating system for evaluating one against another. We have to trust what the manufacturers say, and we all know how reliable that is.
You're 100% correct about that. One tire manufacturer's LRR tire might have a higher rolling resistance value and another's standard tire. Unfortunately, the only way consumers have to really tell is through the personal experience of others with the same car.
@jerry33: If you look at my post on the first page of the thread, you will note my brain's perception of how LRR works. Refuting this, you seem to say that they can be quite grippy. Since you seem to know about this, can you explain how a tire that creates less friction can have the same grip? Or are you saying they are "good enough" but not as grippy as tires that are less efficient? I know there are many variables to consider, and that tire compounds and tread patterns all factor in here, but assuming all other variables are as similar as possible in comparing a comparable "regular" or average rolling resistance tire to a LRR tire is it really true that they can be just as grippy thus just as safe? To me this seems to violate a fundamental law of physics.
School me some knowledge, please. I await your esteemed tutelage, which may or may not involve waving what appears to be an acacia branch or perhaps a small pine tree over me while you wear a long white robe paired with a really big "bride of Frankenstein" haircut. Ok, just pass the Kool-Aid.
Cheers, and thanks.
School me some knowledge, please. I await your esteemed tutelage, which may or may not involve waving what appears to be an acacia branch or perhaps a small pine tree over me while you wear a long white robe paired with a really big "bride of Frankenstein" haircut. Ok, just pass the Kool-Aid.
Cheers, and thanks.
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Sig698
Model S Sig Perf #698
WOW that is heavy! I bet you'd get pretty noticeable gains just from changing to a more reasonably weighted wheel!
You'll have to settle for bowing to the kitsune guarding my house.
Friction and rolling resistance are two separate things. In the simplest terms, rolling resistance is how hot the tire runs (how much energy the tire uses) while friction (traction) is how much shear force is required to have the tire lose contact with the road surface. As tire technology advances--and the book we can write about what is not known about tires is far larger than the book that can be written about what is known--there is more separation between the functions of a tire vs. the parts of a tire.
A short history: In the days of bias-ply tires there was hardly any separation of functions vs. parts of the tire. Any force that acted on the tread also acted on the sidewall and vice versa. Then radial tires came along and they separated the ability of the tire to carry load and provide cushioning from the tread that provided traction and stability. The result of doing this was that rolling resistance went down a significant amount and traction went up along with tread life and flat resistance. The cushioning ability of the tire was improved as well. Looking at a radar graph of the two types of tires you'd see that every category went up. (The radar graph is larger in total area (radius), as opposed to just being larger in one or two categories and smaller in other categories with the same area.) Ideally, tires should be made with the graph being almost circular. However, there is a ways to go, so every tire is a compromise of various qualities.
Example of radar graph (no particular meaning, just the first reasonable one I found):
The first generation of low rolling resistance tires basically traded traction for rolling resistance so the area of the radar graph stayed the same--some of them were pretty slippery. The latest low rolling resistance tires have silica based tread compounds that reduce the energy used without sacrificing traction. A radar graph of these tires is going to be larger in area than the previous generation. Performance tires will make the traction radius of the graph large but reduce other radii (energy use and tread life).
Bottom line is that there's no violation of any physics here. Just improvements--and every so often a very large improvement is made so that the area of the radar graph gets larger.
So will low rolling resistance tires have as much traction as performance tires? Of course not, performance tires have given up things to get more traction--this will always be the case. Will they have as much traction as folks expect in regular non-LRR tires? In most cases, yes. The actual answer for a particular tire depends upon how the tire manufacturer tuned that tire and what tire it's being compared against. However, what you'll likely notice is that the non-LRR tires are the older tires that will eventually go away, and are really still there to provide a lower price point.
I doubt it, under normal driving you'd get a lot of regen anyway. However maybe a wheel that has less drag, sure. These wheels look like giant fans...
I just scouted out my next set of tires to replace the 19" Goodyear Eagles on my P85. (yes I downgraded to 19s for various reasons). I don't particularly like Goodyear tires. I've had them stock OEM on a few vehicles I've owned, and they don't hold the road well at all and treads don't last either.
Having a P85 now, those issues are even worse. The goodyear's slip a lot when I have heavy acceleration. Upon looking at tirerack, I'm pretty sure my next set will be Michelin Primacy MXM4. I found them on my own, then searched TMC for MXM4 and found this thread. Good to know others here feel the same. http://www.tirerack.com/tires/tires...&autoYear=2013&autoModel=Model S&autoModClar=
Benefits I've found for these tires:
Other possible benefits too as it had high ratings for general handling and ride comfort.
So, while I hope my current set of tires last a while, I am looking forward to putting these on my car too.
Having a P85 now, those issues are even worse. The goodyear's slip a lot when I have heavy acceleration. Upon looking at tirerack, I'm pretty sure my next set will be Michelin Primacy MXM4. I found them on my own, then searched TMC for MXM4 and found this thread. Good to know others here feel the same. http://www.tirerack.com/tires/tires...&autoYear=2013&autoModel=Model S&autoModClar=
Benefits I've found for these tires:
- They are LRR, so I'm curious how much that will help with Wh/mile and extend range.
- Longer lasting treadwear (500 vs 440)
- Better traction in rain (AA vs A)
Other possible benefits too as it had high ratings for general handling and ride comfort.
So, while I hope my current set of tires last a while, I am looking forward to putting these on my car too.
Porsche uses special LRR all-season Michelin (Energy?) tyres on the Panamera Hybrid. Sizes are 255/45/19 (front) and 285/40/19 (rear).
According Porsche these tyres save 4% energy compared to the standard tyres on the Panamera.
However I can not find these 19 inch tyres on the Michelin site.
Anyone knows which type of tyres these are ?
According Porsche these tyres save 4% energy compared to the standard tyres on the Panamera.
However I can not find these 19 inch tyres on the Michelin site.
Anyone knows which type of tyres these are ?
Primacy MXM4 most likely. The Michelin web site is hard to navigate--mostly because they are of the opinion that you need to be guided and so they put a lot of helpful stuff in the way of finding what you want. The best way is to google for the tire size and Michelin.
teslasguy
MSP P#1117
My car came with the 21" Contis, but I immediately swapped them out for Tesla 19" wheels and Bridgestone Pole Potenza RS970A all season for the Philly area winter.
They have been great. Here's the rub... i was one of the drivers in the teslaroadtrip drive to groton, Conn and back and my car was always ending up after each leg with 15-2o rated miles less than the other cars.
It seemed that all the other cars were within a mile or two of each other. Tesla engineers went over my logs a number of times looking for the reason. At first they said my car was underperforming the others by around 7%, and it was due to my running the 21" wheels/tires. When I pointed out that I was running 19" they then said that maybe I was leading the pack and therefore encountering more wind resistance. They also said that my car drove more miles than the others. I replied that I was always in the middle of the pack and if anything I was drafting. I also said that I don't understand the extra miles showing that I drove as we were always driving together.
I then decided to set up a 100 mile test drive on I95 with a fellow teslaroadtrip driver and asked that they watch our logs and see if they could spot anything. I told them I was driving the 19" Bridgestones and the other driver would be driving the Goodyear Eagle RS-A2 all season tires. At that I got the following reply... "This is very likely the elusive “smoking gun!” Rolling resistance has a large impact on overall range. The customer is running non-tesla-approved tires; Bridgestone Pole Potenza RE970AS 245/45R19. The size of the tire has less impact on range than does rolling resistance of the tire. Rolling resistance is affected by tire pressure, tread pattern, rubber compound. Also it is worth noting that Tesla evaluated the Bridgestone Potenza tires and chose not to go with them for this very reason. Any further testing the customer would like to perform will likely be inconclusive due to the tire differences.
We would recommend tire replacement to the approved Goodyear tires as well as an alignment. I’ve already relayed this to Nick Terracciano, who will reach out to the customer on both fronts."
They also changed their position on the underperformance of my car to only 1% at the end.
They also said that the logs indicated that my car travelled 3 miles more than one of the other cars (over a course of around 700 miles?).
I'm really surprised by this as 2 or 3 of the drivers were driving 21" wheels/tires, one was driving the pirelli winter 19" tires from Tesla and one driving the 19" goodyears from Tesla. Tirerack told me that they don't consider the 19" Goodyear a low rolling resistance tire. Is it possible that the 19" Bridgestones are really THAT bad at rolling resistance compared to all those other wheels/tires? At any rate I love these tires and have no intention on dumping them for the Goodyears. I will be swapping them out for my 21" wheels in a month or so anyway.
I'd love to hear other thoughts on this issue.
They have been great. Here's the rub... i was one of the drivers in the teslaroadtrip drive to groton, Conn and back and my car was always ending up after each leg with 15-2o rated miles less than the other cars.
It seemed that all the other cars were within a mile or two of each other. Tesla engineers went over my logs a number of times looking for the reason. At first they said my car was underperforming the others by around 7%, and it was due to my running the 21" wheels/tires. When I pointed out that I was running 19" they then said that maybe I was leading the pack and therefore encountering more wind resistance. They also said that my car drove more miles than the others. I replied that I was always in the middle of the pack and if anything I was drafting. I also said that I don't understand the extra miles showing that I drove as we were always driving together.
I then decided to set up a 100 mile test drive on I95 with a fellow teslaroadtrip driver and asked that they watch our logs and see if they could spot anything. I told them I was driving the 19" Bridgestones and the other driver would be driving the Goodyear Eagle RS-A2 all season tires. At that I got the following reply... "This is very likely the elusive “smoking gun!” Rolling resistance has a large impact on overall range. The customer is running non-tesla-approved tires; Bridgestone Pole Potenza RE970AS 245/45R19. The size of the tire has less impact on range than does rolling resistance of the tire. Rolling resistance is affected by tire pressure, tread pattern, rubber compound. Also it is worth noting that Tesla evaluated the Bridgestone Potenza tires and chose not to go with them for this very reason. Any further testing the customer would like to perform will likely be inconclusive due to the tire differences.
We would recommend tire replacement to the approved Goodyear tires as well as an alignment. I’ve already relayed this to Nick Terracciano, who will reach out to the customer on both fronts."
They also changed their position on the underperformance of my car to only 1% at the end.
They also said that the logs indicated that my car travelled 3 miles more than one of the other cars (over a course of around 700 miles?).
I'm really surprised by this as 2 or 3 of the drivers were driving 21" wheels/tires, one was driving the pirelli winter 19" tires from Tesla and one driving the 19" goodyears from Tesla. Tirerack told me that they don't consider the 19" Goodyear a low rolling resistance tire. Is it possible that the 19" Bridgestones are really THAT bad at rolling resistance compared to all those other wheels/tires? At any rate I love these tires and have no intention on dumping them for the Goodyears. I will be swapping them out for my 21" wheels in a month or so anyway.
I'd love to hear other thoughts on this issue.
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