The Verdict: Need More Info
The pensioner route needs a pension, so yours goes another way: temporary residence on economic solvency. Check whether your income or savings meet the figure your consulate publishes, then apply there.
Savings, investments, rent and earnings are not a pension, however large. An annuity or a pension from a former employer for work done abroad may count, so ask the consulate if part of your income is one.
Economic solvency is assessed on monthly income over the last six months, or on an average balance over the last twelve, and you need only one. Remote work for foreign employers or clients fits it; pay from Mexico does not.
There is no national income figure. The law asks only for an income that lets you live in Mexico, and each consulate sets and publishes its own threshold, which moves each February and with the exchange rate. Figures quoted online are one consulate's snapshot; only yours counts.
The first card is for one year, renewable to four, then it converts to permanent residence: the same destination as the pensioner route, four years later. If you start drawing a qualifying pension, you can apply on that instead.
Apply at the Mexican consulate for your country of nationality or habitual residence, not from inside Mexico or after arriving as a tourist. Bring a statement for each month of the period, not an annual summary. A decision takes up to about ten working days, and you must exchange the visa for a residence card at the immigration institute (INM) within 30 days of arriving.