In a nutshell no. Here is my story so far.
This 12V saga left the showroom on 31st December 1991. It was the Iswara Meter Sagas, the last of its type.
This car was running 20W-50 mineral with the API standards of those times, from new till 2004. By 1997, clocking 270,000kms, the engine was already burning oil mildly. The plugs were also fouling mildly, cold starts were usually difficult, and would take about 5-7 seconds of cranking..every day !Oils were changed religiously at 5000km, and they were always duckhams Hypergrade, or Castrol GTX, as everyone said this was just a low end car and will require only low end oil. When starting up, the valves and cams would make some grinding noises and would eventually quiet down once warmed up. White smoke would come out of the exhaust only on revs higher than 3000. At those times, everyone believed engine wear was unavoidable, especially after 200,000kms, and is to be expected. By 1999, white smoke was coming out of the exhaust even at idle ! Starting was always a chore as usual, and I would always add oil additives to counter the burning. In late 99, something rather bad happened to this car. After an oil change, and it was with Duckhams Hypergrade 20W-50. The car ran fine and I took it to work. After work, I started the car. I cant remember the specifics, but a colleague of mine called out to me and said engine oil was pouring out from the bottom.
Upon inspection, I found that the oil filter failed. I had to get the car towed back home, the first time in 7 years of ownership. Thinking it was a bad filter, we claimed a new one from the parts shop, installed a new one, and re filled the oil. My brother went underneath just to check ,and I started the engine, I suddenly heard him screaming at me to stop. He said when I started the engine, the oil filter expanded and gave way at the o rings. We knew we had a serious problem, so we got it towed to a mechanic. He removed the sump, and he found a few short steel chips in the oil filter passage, causing the blockage. I now know that these were wear metals from probably the cylinder block. By this time it was already at 300,000kms. Accepting this as normal and unavoidable signs of engine wear and aging, I went on with this car, maintaining it with the recommended oil, and watching in horror as all the bad signs of an unhealthy engine show up, erratic idling, difficult cold starts, horrible noises, plug fouling, exhaust smoke and soot...I heard about synthetic oils but did not pay much heed to them as they were expensive, and as some one who just started working, I did not have much money.
In 2004, I was earning a better paycheck. I also met a racing gearhead who was also a mechanic, he was meticulous to the point of obsession, so I knew he was the right guy to over haul my engine. August 2004, I let him remove the engine . What he found was bad news all the way. The crankshaft,pistons, piston rings, camshaft, valves, cylinder bore,oil pump, water pump, all were basically in very bad shape. All those had to be replaced. So I gave him the go ahead, and he remachined the cylinder bores as they had ovalized. He put in new bearings,con rods, pistons, rings, oil pump, water pump, camshaft, crankshaft, valves etc..and told me to put only synthetic oils if I wanted it to last. So I boutght 2 bottles of 4L Duckhams QS 5W-40 Synthetic. Of course I ran mineral 20W-50 for 1000km then switched to the synthetic. Well since the engine was like new,everything worked great. No horrible sounds, no smoking, no burning oil, starts were easy(cranks only takes 1 second, even now in 2014), power was there. So OCI after OCI I kept with synthetics, just to see if this was true. I ran the car pretty hard some times , and still the engine sounded and worked really good. I drove up to genting highlands, which is a mountain resort, which has a windy steep road to climb for about 10kms. I drove my car up there 4 times,in the span of 9 years since 2004. Still the engine did not burn any oil, and sounded good. Even the plugs looked good everytime i checked them. They always have brownish deposits and they are dry, all 4 plugs. So far I have clocked 120,000kms.And I hope to clock up to 370,000km, and see if the engine will go as bad as it did on mineral.
As comparison, my colleague who uses the same car (LMST) and same engine, his car left the factory in 2006, and clocked about 120,000kms also, but his is on a steady diet of Shell Helix HX-3 20W-50. He has varnish all over his cams and valve rockers, but look at my valve rockers !
This is how my valves look like in December 2013, I have never took it apart since overhaul in September 2004. Before overhaul my valves had sludge, and my plugs were fouled with oil
He changes oil every 5000km, which is 3000 miles, and yet, his engine does not look as clean as mine, nor sound even remotely as good as mine. Keep in mind the HX-3 is a SJ certified mineral, so it was better than whatever was available from 92-2000. Yet he has varnish in his engine, and may even have some slight sludging issues.
Remember, my car is carb operated and not with EFI, so in theory this should contribute to more deposits, yet I do not see any on my rockers and camshaft.
I am not against mineral oil, if it can keep my engine working as long as it possibly can, but if synthetics can help my engine to retain it peak operation 2 or 3 times longer than dino, then that is what I want.
5W-40 synthetics are not too thin as people always say, and I have proven it. Heck, Shell Helix Ultra 5W-40 performs better than magnatec 10W-40 semi syn. Just stay away from 0W oils , I tried Castrol Edge 0W-40 from Tesco and it made my valves noisy at operating temps. For the first time , I did an oil analysis that costs me 35 USD in april 2014. It confirmed that the Tesco sold Castrol oil was not fake.
The result was pretty good as it shows the oil still has a lot of additives left, as shown by the TBN at 5.7. Also there were no water or fuel in the oil, which shows the engine sealing is very good.
As of 19th april 2014, I filled with AMSOIL fully synthetic 10W-40, which has high zinc and zddp, its been a little more than 9000km and the engine still sounds damn good. AMSOIL guarantee this oil up to 15000 miles, but I intend to change at 15000km or May 2015, and will send this sample to Blackstone for analysis. At 9000km, this amsoil seem to have lost 1/4 quart, and I topped up with whatever is left in the bottle. So far I find Castrol magnatec to be the worst, losing one quart every 3000km.
So this is the list of oils I used since overhaul
1. Shell Helix Ultra 5W-40 Syn (about 8 OCI)
2. Castrol magnatec 10W-40 semi syn (2 OCI)
4. Duckhams QS 5W-40 Syn (2 OCI)
3. BHP Syngard 8000 Syn (1 OCI)
4. Mobil 1 5W-50 Syn (1 OCI)
5. Castol Edge OW-40 Syn 6278kms
6. Amsoil AMO 10W-40
