First 6 months service complete

[Uccello]

We took our Leaf in last week for the first service. I cringed when the service manager brightly said "Oh great, my first Leaf in for service!"

When I picked up the car the worksheet was from a regular ICE vehicle so there wasn't much other than ever other line reading "N/A" I never got the feeling that they did any sort of special Leaf specific diagnostics. They did try to charge me $30 for rotating the tires "because it is an electric car" which I balked at. ($30 being the least amount of money they could charge me- a 20 minute increment)

They finally removed the charge after I told them I wasn't called before the work was done. Seems to me since there is little to do on the car the least they can do is rotate the tires. I'll have to look at the original Leaf manual and see what exactly is included in the first dealer service.

Good luck with your first service!

-john

 

[Randy]

Hi John,
I think I already know the answer to this question, but will ask anyways.

There is a writeup in the Service Manual about how to "Retrain" the pressure sensors inside the tires to broadcast their correct location after they are replaced or rotated. If this re-training is not done, then a "low pressure" message would be for an incorrect tire. Of course, it would get corrected at the next rotation (back to original).

Did the dealer say anything about going through that process? It shouldn't be new for the Leaf as other cars have the same issue.....

Thanks, Randy

 

[TomT]

Not necessarily. Since these are not unidirectional tires, They could use the X pattern which means that it would be a long time before the tires make it back to their original positions... And I'll bet that they didn't retrain them...
The best bet is to find a way to identify the tires original positions (Dot numbers perhaps - that's what I did with mine) and then be able to correlate that to a low tire warning if you get one...

Of course, it would get corrected at the next rotation (back to original).

 

[TangoKilo]

Interesting about the tire sensors needing to be retrained. You learn something every day... Common sense would still prevail that if you get a low pressue warning that you'd check all the tires anyways...

 

[mwalsh]

There is a writeup in the Service Manual about how to "Retrain" the pressure sensors inside the tires to broadcast their correct location after they are replaced or rotated.

I can see retraining being needed if we're talking about a brand new sensor's identity. But on most cars, the TPMS would relearn the new position of sensors it already "knows" by simply by driving the vehicle for a while. Is this not the case with the LEAF?

 

[TomT]

It has no way to know at which corner of the car the wheel is since the vehicle just receives a radio signal from all the wheel sensors and can not determine which wheel is sending it. That is why every sensor has a unique ID and must be trained by telling the system which corner of the vehicle it actually represents. However, if you do rotate the tires and do not retrain the sensors, you can still tell by knowing which corner a wheel was original on... ("Oh, a low pressure alert for the LR... That one is now on the RF.")

There is a writeup in the Service Manual about how to "Retrain" the pressure sensors inside the tires to broadcast their correct location after they are replaced or rotated.

I can see retraining being needed if we're talking about a brand new sensor's identity. But on most cars, the TPMS would relearn the new position of sensors it already "knows" by simply by driving the vehicle for a while. Is this not the case with the LEAF?

 

[evnow]

I thought we need to take the car in once a year - not 6 months. What do they do at 6 months ?

 

[Herm]

can you inflate the tires to the sidewall max without a warning?

 

[DaveEV]

can you inflate the tires to the sidewall max without a warning?

Yes.

 

[derkraut]

can you inflate the tires to the sidewall max without a warning?

Yes.

I'm running with 44lbs cold, front and rear. Been doing that with the Prius for 5+ yrs. Harsher ride, but significantly better energy consumption, and less tire wear.

 

[LEAFfan]

can you inflate the tires to the sidewall max without a warning?

Yes.

I'm running with 44lbs cold, front and rear. Been doing that with the Prius for 5+ yrs. Harsher ride, but significantly better energy consumption, and less tire wear.

I asked a Discount Tire's manager who had been in the tire business for many years about these LLR's and he said if you put more than 5 extra (over 41), you will lose handling such as in an emergency situation, or in rain, snow, stones, etc. and it can be very dangerous.

 

[ebill3]

I thought we need to take the car in once a year - not 6 months. What do they do at 6 months ?

If you are operating under maintenance SCHEDULE 2 (less severe operating conditions), tire rotation is the only service at 6 months or 7500 miles.

Bill

 

[DarkStar]

I'm running with 44lbs cold, front and rear. Been doing that with the Prius for 5+ yrs. Harsher ride, but significantly better energy consumption, and less tire wear.

Ditto, always run max sidewall pressure. No reason not to.

I asked a Discount Tire's manager who had been in the tire business for many years about these LLR's and he said if you put more than 5 extra (over 41), you will lose handling such as in an emergency situation, or in rain, snow, stones, etc. and it can be very dangerous.

Unfortunately they're in the business of selling tires. There is nothing unsafe about running a tire at it's maximum specifications and some people have even reported better handling and braking.

 

[Herm]

Hypermilers use the max sidewall pressure as their starting minimum.. and go up from there. Modern radials are way over designed for burst pressure, but not with bias ply tires such as used in some trucks.

 

[TomT]

Going over the maximum rated pressure on the side wall is like playing Russian Roulette or being a test pilot. This has been discussed in great detail on the forum many times and the bottom line is that it is a sucker's bet and a very bad idea! The fellow at the tire store was giving very sound advice!

Hypermilers use the max sidewall pressure as their starting minimum.. and go up from there. Modern radials are way over designed for burst pressure, but not with bias ply tires such as used in some trucks.

 

[evnow]

The question would be - what is the added risk vs added efficiency gain. I'd say the efficiency gain after certain point is not that great while the risk keeps increasing.

 

[ERG4ALL]

One thing is for sure, the higher the tire pressure the smaller the contact patch. That being said one could also argue that the psi of the smaller contact patch will be greater thereby giving more traction up to a point. And that "point" may well be different for different tires due to belting, number of plies, difference in rubber compound, etc. Without some empirical evidence/testing it's a complex trade off.

 

[Herm]

Very easy to test..

There is more danger in an under-inflated radial, the tire flexes more and can eventually overheat and fail.. plus its much easier to roll the car over. If you are worried about the planet and want to conserve, yet you are worried about your tire blowing up like a cheap condom dont exceed the limits printed on the side of the tire.. they are safe.

http://en.wikipedia.org/wiki/Tire-pressure_monitoring_system

"In the United States, the Firestone recall in the late 1990s (which was linked to more than 100 deaths from rollovers following tire tread-separation), pushed the Clinton administration to publish the TREAD Act. The Act mandated the use of a suitable TPMS technology in all light motor vehicles (under 10,000 pounds), to help alert drivers to severe under-inflation events."

 

[ttweed]

One thing is for sure, the higher the tire pressure the smaller the contact patch. That being said one could also argue that the psi of the smaller contact patch will be greater thereby giving more traction up to a point.

This last statement is a misconception, and no logical argument can be made that it is generally true. A smaller contact patch will not give more traction under any circumstances except for perhaps hydroplaning conditions, when the tread design is unable to evacuate water adequately, and a larger contact patch can result in "floating" the tire above the solid road surface sooner than a smaller one. Is that how you normally use your tires? It is a very poor argument in favor of high inflation, considering the percentage of time you might encounter such conditions, and that lowering the vehicle speed can avoid the loss of traction associated with the larger contact patch in hydroplaning.

Tire grip is a very complex issue, and has been studied extensively for both racing and safety purposes. The area and shape of the contact patch, along with rubber compound, tire construction, and the dynamic loading they are subjected to are the key determining factors in overall grip. You are confusing the pressure of the tire's inflation with the pressure of the "normalized" loading of the tread to the road surface, which does contribute to traction, and is a function of the car's weight and the dynamic loads induced during operation (accelerating, braking, and cornering). Higher inflation can decrease rolling resistance, and help prevent overheating, but it will not increase grip. It can also cause uneven wear by loading the center of the tread area unevenly, compared to the shoulders of the tires.

That said, I have increased the inflation of the Leaf's tires beyond Nissan's suggested level, since economy is more important an aspect of the car than performance. I have chosen 40PSI cold as I am allowing for a 4 PSI increase during highway use, not to exceed the manufacturer's 44PSI max. inflation level. I will be monitoring wear patterns on the tire over the next few thousand miles to see if this is detrimental, as well as keeping tabs on efficiency to see if it really makes much difference.

TT

 

[TomT]

If that was true, race cars would be running bicycle tires with 100 pounds in them which, of course, is not the case. In fact, it actually works just the opposite of the way that you suggested...

One thing is for sure, the higher the tire pressure the smaller the contact patch. That being said one could also argue that the psi of the smaller contact patch will be greater thereby giving more traction up to a point. And that "point" may well be different for different tires due to belting, number of plies, difference in rubber compound, etc. Without some empirical evidence/testing it's a complex trade off.