Recently put a Jasper engine in my 89 pickup. I used Castrol 10W-30. This is the only engine I ever use. I put about 180 miles on my engine and finally got a chance to have it changed.
Since I purchased a lifetime alignment from Firestone I had them do an alignment, balance and rotate tires, and then change the oil and filter using the oil I provided. (They do not have Castrol)
I picked up my truck and immediately realized that the oil and filter I provided was still in the bag in the passenger seat. Firestone only charged my for labor on the oil change part, so how did they overlook such a simple request!? I immediately walked back in and asked why they didn't use my oil. The manager stated that they would pull it back in and change it again, but I didn't have the time. I might just have them change it again for me again this weekend.
This is exactly why I swapped my own engine. I'm not engine expert and sometimes rely on this board. But when it I want something done properly, there's only one person I can rely upon....myself. I'm almost done ranting.
So is it bad to mix different brands of oil? They didn't exactly flush every drop of Castrol before filling it with Kendal, so there is some Castrol mixed in it. How do I know if Firestone even used 10W-30? It may not be bad for the engine, but it sure does bother me that they can not follow directions. How can I trust them to do an alignment properly?
In addition, Firestone charges $9 per tire to balance and rotate. But $11 per tire will get you the same for as long as you own the vehicle. They will not tell you this, but all you have to do is ask. I am not happy with the customer service that Firestone provides, but I feel like I am vested. A lifetime alignment costs $120. It paid for itself many years ago, so maybe I'm not really vested, I just feel like it since I just paid $11 per tire for a balance/rotation. (They charge more if you purchased the tires through another merchant.)