well in my 2 fords , my tarus was back spec'd to 5w20 and my wifes freestryle spec'd to 5w20
I have been running 5w30 in them both , tarus is a vulcan 3.o and Freestyle is a DOHC 3.o duratech
tried a bosch 3402 filter VS motorcraft , both quiet on start up VS motorcraft filters
Been running QSUD in Freestyle and Tarus is work Car trialing Proline 5w30 with great results ,
In your area 5w30 ( any good quality) oil will work fine we have much colder weather in Il then TX and we have heat in the summer ,,and no starting problems this winter
IMHO 5w30 in TX , ask the cops what they run in the squads and that will be the ultimate test for oil in TX heat
I have been running 5w30 in them both , tarus is a vulcan 3.o and Freestyle is a DOHC 3.o duratech
tried a bosch 3402 filter VS motorcraft , both quiet on start up VS motorcraft filters
Been running QSUD in Freestyle and Tarus is work Car trialing Proline 5w30 with great results ,
In your area 5w30 ( any good quality) oil will work fine we have much colder weather in Il then TX and we have heat in the summer ,,and no starting problems this winter
IMHO 5w30 in TX , ask the cops what they run in the squads and that will be the ultimate test for oil in TX heat