Tesla has decreased prices for the 100D and P100D variants of its Model S sedan and Model X crossover SUV.

Saying its most expensive products are more efficient, the sticker reduction amounts to roughly 3.5 percent on each model. Specifically, the Model S 100D has been reduced by $3,500 to $94,000. The performance version of the Model S, the P100D with Ludicrous mode, sees a $5,000 cut to a new price of $135,000.

Shopping for a Model X? Tesla has you covered there, too. Its Model X 100D also experiences a $3,500 reduction and now starts at $96,000. Hot rod customers seeking a speed fix in Tesla’s Model X P100D with Ludicrous mode will save $5,000 with its new price of $140,000.

The new prices are currently shown on the Build and Price tool of Tesla’s website, which promises late October delivery for a custom-ordered Model S or Model X. The price drop will apply to new buyers and existing 100D/P100D buyers who have not yet taken delivery of their new Tesla. A similar price cut of $3,500 was applied to the Model X 75D earlier this year.

A Model X P100D is billed as the world’s fastest accelerating production SUV, using its Ludicrous Speed upgrade and all-wheel drive to hammer its way to 60 mph in less than three seconds. The same powertrain pushes the Model S P100D to 60 mph even more quickly, while promising a range of over 300 miles on a single charge of its 100kWh battery.

It would appear from these pricing changes that Tesla is enjoying significant economies of scale at its Gigafactory in Nevada. As the cost of producing lithium-ion batteries decreases, it is not beyond the realm of possibility that we will see more price cuts in the future.

Putting on our speculation hats while shamelessly stoking the rumor mill, these price reductions may also be in response to the potential evaporating of federal EV tax credits.