San Luis Potosí → Zacatecas · Autopista 57D México-San Luis Potosí
On heavy-rain or dense-fog days the San Luis Potosí, San Luis Potosí, to Zacatecas, Zacatecas, leg routinely demands well more than the 2h 28m estimated: Autopista 57D México-San Luis Potosí carries known hydroplaning hot spots and reduced-visibility corridors that justify dropping to 35 mph through a few short stretches. The outbound run covers 222 km (138 miles) over varied topography between San Luis Potosí (the capital potosina y nodo logístico que conecta el Bajío con el norte del país) and Zacatecas (the capital zacatecana y patrimonio minero colonial reconocido por la UNESCO), demanding sharper attention on mountain descents and shoulder-less curves. Before pulling out, check brake-pad wear, tire tread depth, and washer-fluid level in the reservoir. Fuel spend holds near MXN 447.70 for the 18.5 liters (4.9 gallons) consumed. Even in adverse conditions, the flat tariff of MXN 6.50/km guarantees the standard outbound payout of MXN 1443.00 — log any incidental costs (extra toll, mandatory meal, emergency lodging) in a separate field on the Clara receipt. For the UK professional driving the 222 km (138 mi) between San Luis Potosí and Zacatecas, reimbursement of MXN 1443.00 fits the subsistence allowance regime when paid at or below HMRC AMAP rates of 45p per mile for the first 10,000 business miles in the tax year. UK firms reimburse at HMRC AMAP rates (45p / 25p per mile) so the payment stays free of PAYE and NIC under approved mileage allowance payments rules. Retain a VAT receipt accepted by HMRC for input-tax recovery from the BEIS-tracked forecourt network forecourt used to refuel; His Majesty's Revenue and Customs (HMRC) compliance officers cross-reference fuel VAT receipts with the P11D return when reimbursement exceeds the approved rate. Excess paid above AMAP on the San Luis Potosí→Zacatecas run must be reported via PAYE settlement agreement or it becomes a benefit-in-kind on the employee's tax code.