My 2 cents- I think M. Wraight has it right. I've owned three Zu Rodeo 3.2s that as soon as I purchased them, I changed the oil to the recommended 10W30- and have followed the Haynes, Chilton recommendations, as well as the recommendations of Isuzu stealership "mechanics" regarding the use of 10W30 crankcase oils, and every time the engines ( perfect mechanically) rewarded my efforts with the ticking valve noise, however, EVERY time I switched over to 10W40 synthetic blends, The "noisy lifter syndrome" that seems endemic to these engines has faded into memory. Now, I live in Hawaii, and it's warm here all year 'round-so using a lower viscosity oil has no observable advantage for me. If you live where you encounter cold or freezing temperatures regularly, this probably is'nt for you. All I can say is after close to 400,000 accumulated miles on these three vehicles using 10W40 synthetics (a little more $-But worth it to me) I have NEVER suffered an oil related problem or malfunction, and the best part is my engines have'nt sounded like there are ball bearings rattling around under my valve covers since! But I still can't stress enough-Change your oil regularly!!(every 3000 miles) at least, follow the recommended maintenance procedures and change that timing belt, tensioner(As well as your Water Pump!) after 60,000 miles. Your Zu will love you for it!
ToddZ Kailua-Kona Hawaii
Last edited by Toddz
on Wed Feb 04, 2004 2:25 am, edited 1 time in total.