I changed my oil with conventional 5-20. The car is burning a lot of oil. about a quart in 250 miles. I will prob change it with 10-30 and try a product like Restore. Also the car sat for about 5 years before i did the oil change so im wondering if it will improve after a while. Any recommendations? It runs strong a little shudder when it starts but then smooths out in about 5-10 seconds.