It tends to work out better the more expensive the cars involved, and when the car being traded-in is not very old with low mileage and in great condition.
For a $30K car, if the trade-in price is:
- $20K, tax savings = $1,325
- $10K, tax savings = $662
For $50K car, if the trade-in price is:
- $40K, tax savings = $2,650
- $30K, tax savings = $1,987
For $100K car, if the trade-in price is:
- $70K, tax savings = $4,637
- $60K, tax savings = $3,975
For $250K car, if the trade-in price is:
- $225K, tax savings = $14,906
- $200K, tax savings = $13,250
Anyway, for people who didn't already know/understand this, the math is simple:
- Trade-in Offer + (Trade-in Offer x Sales Tax Rate) - Private Sale Offer = N
If N is greater than zero, the trade-in is the better deal.