Posted By email@example.com on 06-25-2011 10:10 AM
I just changed the oil in my '97 GMC half ton yesterday. It takes five litres (quarts?) and I found a 5 litre container at my local big box...nice! It wasn't until afterwards that I noticed it's 5-20 wt, not the 5-30 I usually use. Summer temperatures here usually range from 75-95 F (20's-30's C). Do I need to change my oil again?
Some of the newer 'Hi-Tech' engines call for 5W-20 oil due to the 'tighter engine tolerances' and also for 'eco' (higher gas mileage) reasons. Use the oil that is recommended by your owner's manual for your engine, unless it is 'high-mileage' and has shown signs of 'oil consumption' recently.... if so, then a higher rating oil might be beneficial. The type of driving you do can also determine the best weight oil you should be using too. City and stop-and-go driving puts your engine under more stress and usually HIGHER ENGINE AND OIL TEMPS than highway cruising speeds do and I'd recommend either a synthetic oil or syn-blend oil be used under those driving conditions. I run FULL SYNTHETIC in all my vehicles and every one of them, except my NEW 2011 Nissan Frontier PRO-4X, has over 300,000 miles on them - without any oil-related engine problems to date.
One question that I have is, "What does it look like inside your valve cover opening under the oil filler cap?"
If you have a 'HEAVY SLUDGE' build-up, then your engines oil passages are getting 'clogged-up' and restricting oil flow somewhat. If so, then you need to use a 'high-detergent' oil like Pennzoil or a high-detergent additive like "Risolene" to clean out some of that sludge and build-up in the oil passages. This will also clean deposits out of hydraulic lifters and eliminate a lot of 'tappet noise' on cold engine start-ups too.
I'll try to locate some of my older postings on both oil and oil filters and update them for our members. There is a lot of useful and informative web sites out there for those who want to me MORE KNOWLEDGEABLE about modern lubrication products. A lot of improvements and changes have been made since the oils our fathers used and in our 'youth' for some of us 'old geezers'. LOL
If you decide to replace your 5W-20 oil with 5W-30, then you can SAVE YOUR 5W-20 oil in the container it came in and use it for 'top-off' oil between oil changes. The small difference in 'oil weight' will not make a difference under those conditions.... and you won't have thrown money away by making the change now. It would also make an IDEAL general lubrication oil for general use around the house too by putting some in one of those 'oil squirt cans'.