We are big promoters of FilterBarn, and for years have purchased all our filters from them.
But today, when I tried to place over $200 worth filters, I found they are not carrying the same filters we have purchased from them before. Some of their substitutes are acceptable, but in several important cases, their recommended alternatives are not acceptable or are too much of an unknown.
We have found some of our choices at FinditParts & Amazon, but we would end up buying from multiple places and not benefiting from 'no extra cost shipping', and the prices are sometimes higher.
Where are filters being purchased online at favorable prices?
I've been keeping an eye on EBay, found some really great buys on filters. Purchased 2 fuel filters for half the price NAPA wanted for 1, and they were shipped from Canada great time to buy when a strong dollar.
Try Here Free shipping on 250.00 orders
I buy quite a bit for my semi truck
Heavy Duty Truck Parts, Truck Repair Tools, Shop Safety Products (http://www.ryderfleetproducts.com/ryder/)
Check out FleetFilter. Jc
For the limited amount of filters a one-RV-owner buys, I would think amazon or the local NAPA or truck supply store is fine. Buying 10 fuel filters and having them set for 10 years makes no sense.
Oil changes are 5 to 10,000 miles or more (I think I did about 15-20 on my last running synthetic, based more on hours...and I have sample to send off). Fuel filters don't need changed as often as people claim, unless you have dirty tanks. Air filters are probably over-serviced on an RV that many put 5,000 or fewer miles on a year.
I got a donaldson oil filter off amazon for cheaper than any where else I could find it.
Heavy Duty Truck Parts, Truck Repair Tools, Shop Safety Products (http://www.ryderfleetproducts.com/)
I have purchased from Ryder Fleet Products before with good results. Also, your local Fleet Pride store is a good source. They have most everything you need for Diesel engines, filters and parts.
FinditParts (http://www.finditparts.com/search?utf8=%E2%9C%93&s=baldwin+filters&commit=)
Not sure how prices compare with Filter Barn.
We have also been using Filterbarn for all of our filters and over the years found them with the lowest prices especially with no shipping cost.
Two months ago for our last big order, we also found that there was a lack of Fleetguard offerings. Their reply to my email asking why the change told me they are transitioning to Baldwin filters as their primary line of filters and will no longer be carrying Fleetguard.
Amsoil does have filters that we use, can use them with Dino oil, they are good quality.