cmcgairty Report post Posted July 1, 2009 Just purchased a used RV with a Onan Emerald 7000 generator with just over 2,000 hours. I don't know the type or grade of oil previously used. Any recommendations? Also, thoughts on regular oil vereses synthetic. Share this post Link to post Share on other sites
tbutler Report post Posted July 1, 2009 Welcome to the forum cmcgairty, I just checked the Cummins website and quickly found the Cummins Onan site which has an RV Generator Handbook. Here is the web address for that: http://www.cumminsonan.com/rv/handbook/ The handbook has recommendations for oil without reference to specific models so it seems to be a blanket recommendation you could use. This is a comprehensive resource that would be valuable to any Cummins Onan Generator owner/operator. Unfortunately, I didn't find your specific model of generator listed in the listing of generator models. Not sure but suspect that the 2000 hours indicate an older model name that wasn't included in this handbook. However, there are resources on that site that should be useful including contacts for customer support and technical documents. You can also find service centers. I'm betting that if you can't find technical documents for your model that customer service will be able to help you. You should be able to get a replacement owners manual from Cummins. I have always found their support to be quite good. Give them a call or e-mail request, I'm sure you'll get a response. Share this post Link to post Share on other sites
traderdude04@yahoo.com Report post Posted July 6, 2009 We use Synthetic 10w-40 in our Onan 5500 because of the high heat of these air cooled engines. Share this post Link to post Share on other sites
