Walmart had 5qt juggs of Pennzoil HM 10w/40 on clearance for $9 and Pennzoil Euro Formula 0W/40 for $13. I almost bought them with the intention of mixing them to run in my 91 K1500 with 4.3 V6. It is spec'd for 5W/30. It has enough wear that the 40 wt won't hurt it. But, I have five 5qt containers of Havoline HM and one 5qt container of Pennzoil yellow bottle. That's enough for 3 years in my truck should I keep it that long.