Hello everyone,
I have some questions about oil I would like to ask. I have a 1991 Chevy K1500 Silverado pickup with a 4.3 V6 engine. The truck now has about 180,000 miles on it, and I am the only person to change the oil since I purchased the vehicle new. I have only used Castrol GTX 5W-30 conventional oil and NAPA / Wix filters and I have changed the oil & filter about every 3,000 miles. When the vehicle was new, I actually did the first change at about 500 miles, another at about 1,500 and then started a 3,000 change interval after that. The oil specified for this engine when it was new was actually SG.
Originally, I went with a plain conventional oil because back in 1991 there seemed to be a big difference in the price of synthetic oil and conventional oil. Also, at that time, I had concerns that synthetic might cause the front or rear main bearing seals to leak, but as I understand it, that is no longer a problem with modern synthetics.
Recently I was only able to purchase Castrol 5W-30 in the Ultraclean synthetic blend, however the price went up to about $ 29.00 for a 5 quart container. I contacted Castrol but they would not tell me what percentage of the Ultraclean is synthetic and what percentage is conventional oil.
I want to stick with Castrol oil. Since there is not that great of a price difference between the synthetic blend and the full synthetic castrol in a 5W-30, should I go with either the "Edge" or Magnatech full synthetic, or just stick with the Ultraclean ? I mainly want to make the engine last as long as I can. I'm not really interested in the "high mileage" Castrol, because as I understand it, the high mileage oil has seal conditioners that may swell seals. I do not currently have a seal leakage problem, so I do not want to swell the seals and cause them to wear, I would rather keep the seals as they are. Also, the high mileage is still a synthetic blend and not full synthetic.
Castrol offers the highest engine warranty for Edge, then Magnatech, and then Ultraclean. I can't use a warranty, but I'm thinking this may give a little clue as to which oil might make the engine last the longest. I think there was a Volvo that got over 2 million miles on plain GTX conventional and is till going, but this was probably all highway miles.
I mainly drive about 16 miles to and from work everyday, mostly highway, but I do make a lot of short trips two days out of the week. Last winter in Ohio, I think it got down to about 10 below and with the regular conventional Castrol 5W-30, the engine cranked over so slow I did not think it was going to start and it did take a little longer to get oil pressure. This is one reason I am thinking a full synthetic may be the way to go now that there is less of a price difference with the synthetic blend.
The engine still seems to run like it did when it was new, same oil pressure, no bearing noise on startup or lifter tick or anything, no smoking. The last oil change I went to about 4,000 miles and it seemed to use about 1/2 quart of oil in that time. If anything goes out, I tend to think it might be a timing chain, but I think by 1991 they did away with the nylon camshaft gears and went to a metal gear didn't they ? If the timing chain has a metal cam gear and a tensioner I would feel better about getting more miles out of it, but I have not looked at it and don't know the exact arrangement. I am pretty sure this engine has rollers on the hydraulic valve lifters that mate with the cam lobes.
I am leaning towards going with the lowest priced Edge Castrol synthetic at my next oil change and then sticking with that. Please let me know what you guys would recommend. I would appreciate any feedback.
Thanks for your help.
Sincerely,
John
I have some questions about oil I would like to ask. I have a 1991 Chevy K1500 Silverado pickup with a 4.3 V6 engine. The truck now has about 180,000 miles on it, and I am the only person to change the oil since I purchased the vehicle new. I have only used Castrol GTX 5W-30 conventional oil and NAPA / Wix filters and I have changed the oil & filter about every 3,000 miles. When the vehicle was new, I actually did the first change at about 500 miles, another at about 1,500 and then started a 3,000 change interval after that. The oil specified for this engine when it was new was actually SG.
Originally, I went with a plain conventional oil because back in 1991 there seemed to be a big difference in the price of synthetic oil and conventional oil. Also, at that time, I had concerns that synthetic might cause the front or rear main bearing seals to leak, but as I understand it, that is no longer a problem with modern synthetics.
Recently I was only able to purchase Castrol 5W-30 in the Ultraclean synthetic blend, however the price went up to about $ 29.00 for a 5 quart container. I contacted Castrol but they would not tell me what percentage of the Ultraclean is synthetic and what percentage is conventional oil.
I want to stick with Castrol oil. Since there is not that great of a price difference between the synthetic blend and the full synthetic castrol in a 5W-30, should I go with either the "Edge" or Magnatech full synthetic, or just stick with the Ultraclean ? I mainly want to make the engine last as long as I can. I'm not really interested in the "high mileage" Castrol, because as I understand it, the high mileage oil has seal conditioners that may swell seals. I do not currently have a seal leakage problem, so I do not want to swell the seals and cause them to wear, I would rather keep the seals as they are. Also, the high mileage is still a synthetic blend and not full synthetic.
Castrol offers the highest engine warranty for Edge, then Magnatech, and then Ultraclean. I can't use a warranty, but I'm thinking this may give a little clue as to which oil might make the engine last the longest. I think there was a Volvo that got over 2 million miles on plain GTX conventional and is till going, but this was probably all highway miles.
I mainly drive about 16 miles to and from work everyday, mostly highway, but I do make a lot of short trips two days out of the week. Last winter in Ohio, I think it got down to about 10 below and with the regular conventional Castrol 5W-30, the engine cranked over so slow I did not think it was going to start and it did take a little longer to get oil pressure. This is one reason I am thinking a full synthetic may be the way to go now that there is less of a price difference with the synthetic blend.
The engine still seems to run like it did when it was new, same oil pressure, no bearing noise on startup or lifter tick or anything, no smoking. The last oil change I went to about 4,000 miles and it seemed to use about 1/2 quart of oil in that time. If anything goes out, I tend to think it might be a timing chain, but I think by 1991 they did away with the nylon camshaft gears and went to a metal gear didn't they ? If the timing chain has a metal cam gear and a tensioner I would feel better about getting more miles out of it, but I have not looked at it and don't know the exact arrangement. I am pretty sure this engine has rollers on the hydraulic valve lifters that mate with the cam lobes.
I am leaning towards going with the lowest priced Edge Castrol synthetic at my next oil change and then sticking with that. Please let me know what you guys would recommend. I would appreciate any feedback.
Thanks for your help.
Sincerely,
John