I wrote an email to Tesla, Goodyear and Dunlop on this matter, but after many weeks I still got no answer. Numbers: - acc. Edmund the actual curb weight of model S is 4.770 lbs at 47/53% weight distribution. this results in a load of 2.528 lbs on the rear tyres. - model S would take 5 adults, each 180 lbs, makes a total of 900 lbs. Looking at the position of people in the car I estimate 40/60% weight distribution. This makes 540 lbs on the rear tyres. - The trunk (directly above the rear tyres) I guess should be able to handle 250 lbs of luggage. Total static load on the rear tyres now is 2.528 + 540 + 250 = 3.318 lbs or 1.659 lbs per tyre. Now if my calculation is correct this means that the max. allowable load on the rear tyres is exceeded in this extreme case. Load index 96: max. 1.565 lbs. Load index 98: max 1.653 lbs. Furthermore it surprises me that similar ICE vehicles (i.e. Panamera) have lower curb weight but much higher load indexes for the rear tyres (101 - 107). Maybe because of their higher top speeds ? For my model S (hopefully to arrive in Oct) I will be considering tyres with a higher load index, just to be on the safe side. Any comments ?

The 19" goodyears have a lower load index than the 21" continental/michelins. FWIW: The sticker on the door says 5710 lbs // 2590 kg GVWR. GAWR (Gross axle weight rating) says 2813lbs front and 3131 rear. Your numbers are higher than these, I would say you have overloaded the car in this case. It looks like it was not designed to handle 5 adults and 250lbs of luggage. I'm not an expert though.

One thing I can tell you about load index is that a higher index can really improve handling in a heavy car.

Correct, I agree, and if you do not exceed GVWR you will also not exceed max. allowable tyre load. GAWR rear is 3131 lbs, which is 1565 lbs per tyre and (how fortunate) exactly the max. load with load index 96 ! Total max. allowable weight passengers plus luggage = GVWR minus CURB weight = 5710 - 4770 = 940 lbs ( ? ! ) . - - - Updated - - - Just had a thought. Does the GAWR include weight of the wheels and tyres ? I guess if GAWR stands for load on the axles you should not add weight of the wheel/tyres. Then the max. allowable weight of passengers and luggage would increase with the weight of all 4 wheels/tyres. So I can take all of my children on a holiday .

Tesla lists the curb weight (http://www.teslamotors.com/models/specs) as being 4647.3 lbs with a 48/52 weight distribution ...

Shifting the weight distribution of people to 55/45 (which I think may really be 50/50), and bringing your luggage down to 200 lbs, you should just make it. Peter In this case the luggage would go in front.

Yes it does. GAWR is what the scale would show for that axle. You are not to exceed either the GVWR or GAWR. This should be possible if you put the luggage in the front. (Duffle bags work better than hard shell cases and are lighter.)

There will be weight differences between 60 en 85, Panoroof and childrenseats in the back. Edmunds put the 85 on a scale and got 4.770 lbs with 21 inch and panoroof.

20mm wider rear tyres from the Performance Plus Package are Michelin Pilot Sport PS2 265/35R21. These tyres have load index 101. Seems to prove your point.

Ah yes, I had forgotten that the specs represent the base model and so do not include the weight of the larger capacity battery nor the seats. Thanks for the clarification.

So why do we have these limits if we start crossing them? Limit == limit, otherwise, increase the limit. Simply going over the limit because it's over engineered wouldn't be a very wise decision imho. I'll follow this discussion closely since I have the same questions as Hans.

Index schmindex, if you load up this car simply put 4+ pounds more air pressure in the tires, especially the rear tires. My oem tires (Goodyears) have max pressure of '51 pounds' which is a bit more than the door placard lists. --

Does anyone have some thoughts on these tires for a stagger on the original 19" wheels. The ratings of this tire are very good, they are fairly cheap and the diameter is the same front to rear. Size UTQG Max Max. Tread Tire Rim Meas. Sect. Tread Overall Revs Service Description Load Inflation Depth Weight Width Rim Width Width Diam. Per Load Range Press. Range Width Mile Bridgestone Potenza S-04 245/45R19 280 AA A 1653 lbs. 51 psi 10/32" 30lbs. 7.5-9" 8" 9.6" 9" 27.7" 753 98Y SL Rear 275/40R19 280 AA A 1819 lbs. 51 psi 10/32" 33lbs. 9-11" 9.5" 10.9" 10" 27.7" 753 JP * 101Y SL

What's with the '51 pounds' ratings? 51 Psi = 351632.62195 pascals So that's not it (not a round number). --

This is probably better suited to a new thread, but I'll reply here anyways... My next set of tires is probably the Potenza S-04. They look to be an excellent tire, and are fairly cheap (esp since they are on sale now @ tire rack). There are others with a 245/275 staggered setup. (Zextraterrestrial comes to mind). I'm not a handling expert, but AFAIK you'll introduce more understeer with wider rear tires.

I think a better explanation of the change would be that it will reduce oversteer. To me, the stock 19" rear tires look tiny from behind. Anyone have a link to info about a 245/275 staggered setup. Zextraterrestrial?

How different wheels/tires affect MS using the P+ package as a guideline That post and 3-4 posts down from there he talks about his setup. I'd suggest sending him an PM to discuss specifics if you don't get an answer to your q's from that thread.