Ok, I see where you're trying to accomplish.
BUT, and to be honest with you here, I don't think it's worth it. Why?
Well, simply put, I believe that when you go mixing these oils trying to incorporate the best of both worlds, all you end up doing is degrading the best characteristics of each oil.
For example, with the 10w30, you'll heavily decrease its cold start flow capabilities. With the 15w40, it will be so "watered down" that benefits of higher HT/HS values, higher TBN levels, and higher levels of deterents/dispersants will be very minimal at best.
I guess the vehicle this mix would go in is a '97 Ford Thunderbird??
If so, have you ever considered something like Rotella-T 5w-40?? Seeing as you're in TN, this would give you a great year-round oil. It definitely has the cold pump specs to match the 10w30 you'd use in winter anyways, why providing you with the full-out, non-diluted higher protection levels of an HDEO.
Using Rotella 5w-40 makes a bunch more sense to me than mixing oils together, but hey, it's your car, and thus your call....
$12/gallon at Wal-Mart...combine that with a Motorcraft filter purchased there as well and you'd be set.
I'll be expecting the diploma shortly.
BUT, and to be honest with you here, I don't think it's worth it. Why?
Well, simply put, I believe that when you go mixing these oils trying to incorporate the best of both worlds, all you end up doing is degrading the best characteristics of each oil.
For example, with the 10w30, you'll heavily decrease its cold start flow capabilities. With the 15w40, it will be so "watered down" that benefits of higher HT/HS values, higher TBN levels, and higher levels of deterents/dispersants will be very minimal at best.
I guess the vehicle this mix would go in is a '97 Ford Thunderbird??
If so, have you ever considered something like Rotella-T 5w-40?? Seeing as you're in TN, this would give you a great year-round oil. It definitely has the cold pump specs to match the 10w30 you'd use in winter anyways, why providing you with the full-out, non-diluted higher protection levels of an HDEO.
Using Rotella 5w-40 makes a bunch more sense to me than mixing oils together, but hey, it's your car, and thus your call....
$12/gallon at Wal-Mart...combine that with a Motorcraft filter purchased there as well and you'd be set.
I'll be expecting the diploma shortly.
)