so i just got my 02 GT (16k miles) and was looking through the maintenance guide. Ford suggests that under normal conditions you should change the oil every 5k miles. I don't push my cars very hard, very rarely drive in traffic, usually put about 8 or 9k miles per year on them and always use synthetic... so is the 5k mile rule something I should follow? It also asks for 5w-30.. now I always grew up hearing people say that they only use 10w50 or 10w40 at the least, is 5w30 good enough? (i live in texas btw, lowest temp is probably 30, highest about 102)
The problwem with running synthetic past 3000(or 5000) miles is not that the oil can't do it's job. Synthetics can actually last up to 10,000+ miles but you get too many contaminants after the 5k point. With mineral based oils they lose viscosity and become contaminated by 3-5k. As for changing to 10w-30 or 10w-40,with synthetics you may not have a choice,I've only seen 5w-30's. Regular oil I wouldn't recommend it cause ford has done alot of research to see what works best in all conditions. I don't think you'd hurt the motor but you might lose some power due to the heavier weight.
Depending on your year of car, 5W-20 is "recommended," but there are only a handful that make that oil. Just get a jug of Mobil 1 5W-30 from Wallyworld, a Motorcraft filter, and don't look back. As many others will tell you, the difference in the oil is minor, and was only done by Ford to meet certain requirements.
