200,500 miles. Previous owner put in engine with 80,000 miles in when jeep had 115,000 on it. Supect poor maintance, oil pump went out and engine seized up. I have put in radiator (twice, stupid plastic end caps), water pump, hoses, tune up items, thermostat, front struts, upper and lower ball joints, tie rod ends, sway bar bushings, front wheel bearing hubs, rear shocks, iac valve, tps sensor, oil pressure sensor, fuel filter, blower motor and resistor with wiring harness ends on both, and oxygen sensors. Put on dual stainless exhaust and cold air intake. Ac blows frigid even in Arizona heat. Original transmission. I use 10w 40 here as well. Summer temps here can reach 120. I burn a little oil. Use the engine flush in a bottle every other oil change and use a full synthetic oil. With higher weight oil i burn allot less