I have a 2000 Toyota Rav4 with 145,000 miles. I bought it when it had 60,000 miles, and it has always used some oil. It burns about 1-2 quarts every 3,000 miles ? not so bad, but it will burn as much as 1 1/2 quart in 600 miles on a long road trip. On my last 3,000 mile trip, it went through about 4 quarts. I have tried all the recommended remedies including heavier oil and additives, but none have helped on long trips. I am torn between just continuing to add oil until the vehicle drops or rebuilding the engine. I am looking for answers to the following questions: Will the oil consumption damage the catalytic converter? What problems should I anticipate if I continue to use the vehicle for long trips? I have a local mechanic who would rebuild the engine for about $2500 (I live in an area where labor costs are low) ? would it be worth it or am I already looking at other problems (such as catalytic converter damage)? The vehicle looks great, runs fine right now, and it is very useful as a work vehicle ? what is the best way to keep it going?