This has probably been discussed and dissected in various ways by some of TMC's number-crunching experts on various threads but, is there some distilled wisdom here? What could the range be on the EPA 5-cycle test for the various battery packs?! 85 kWh Performance - ??? 85 kWh - 265 miles vs the 300 miles at a constant 55 mph (320 miles in the old 2-cycle test) (I assumed above that Elon/JB's blog was referring to the base 85 kWh config rather than the Perf which will surely be lower in the 5-cycle range department) 60 kWh -??? vs the 230 miles at a constant 55 mph 40 kWh - ??? vs the 160 miles at a constant 55 mph I posed this question to a Tesla prod specialist but, she didn't have anything to add at this time. Any educated guesses beyond simple math ratios?! Thanks in advance.

Motor Trend took a stab at it (this explains the two different test methodologies too): Topline 300-Mile Tesla Model S Projected to Earn 265-Mile EPA Range - WOT on Motor Trend They stuck to the simple 12% loss math to arrive at 203 / 141 for the 60 / 40 packs.

EPA has changed the test on how to rate mileage on EVs between the time the roadster was released and now. It used to be a 2-cycle test. Now it's a 5-cycle test. the ne test seems to be a 'more realistic' measure that is 'less optimistic' resulting in lower range estimates.

That's a good point too; Tesla never indicated which mode (range or normal) all the published numbers so far have been clocked at. Normal mode numbers are probably better to work with given that range-mode charging 'hurts' the battery pack some.

Sounds reasonable to me. BTW, the 300 mile number is actually the (probably rounded) range @ 55 mph. The 2-cycle test number is 320 miles.

Well, in the few cases where you really the need the full range, you'll probably use range mode, unless the standard mode gives you just enough, by coincidence.

On the 60 and 85 packs, yes. The 40 kWh is a different animal, as the difference is small to begin with. My plan for the 40 is to use standard mode, and never plan to make a trip longer than standard modes stated range. I can allways access the bottom 10% (guess on percentage) if I get into trouble. Charging in range mode on the 40 will only give you about 10 miles that you would not otherwise have access to, but will damage you battery, and eventually render a pack that is just barely big enough to be just a little bit to small. Battery degradation is going to be critical on the 40 kWh Model S.

That's a valid point, as then you are more frequently at that range. (Though you might still use it a small number of times a year, at least.)

Perf will have the same EPA range since the car is driven exactly the same way. At 311.8 watts/EPA-5-cycle-mile, the 60 kWh battery goes 187 miles and the 40 kWh battery goes 125 miles. There may be some variations from car weight differences, as well as top-off/actually out battery performance.

@smorgasbord - I thought the Perf has better cabling, PEMs, etc. As such, shouldn't resistances and losses be (perhaps immeasurably for EPA) slightly less? I guess I'm saying, if anything shouldn't the Perf get better results than non-Perf?

Theoretically, probably a little better...but probably the tire size choice has a larger impact than this stuff. Tesla has already stated the two get (for all intents and purposes) equivalent range.

For the presumably normal driving in the tests larger cable size shouldn't matter. If you aren't pushing large currents the resistance difference probably won't show up.

The variations should be significant, if 160 miles/40 KWh and 230 miles/60 kWh, vs 300 miles/85 kWh, at constant 55 mph, are anything to go by. Compared to that, the 5-cycle test might have both advantages and disadvantages for a lighter pack: the high-speed test emphasizes aero versus weight, while tests including acceleration at city speeds, further emphasizes weight.