I'd go with a mid-range syn oil. Local driving is actually pretty hard on engines, despite the distances being typically short. Morning start ups, then 30 mins of stop start driving, then engine shuts off. Repeat in the evening. While the local temp does not go low or high enough to warrant a really expensive fully syn oil, what would the price difference be between a mineral oil and a mid range syn?
IMHO, SG driving could consists of a lot of start/stop traffic and/or short distances which typically puts the vehicle to operate in "severe condition" Most owner handbook would recommend oil change ( mineral or synthetic) halved of that of the regular interval i.e. 10k becomes 5k. Why it is not practiced, I don't know and as most can't see inside the engine, ignorant is bliss.
So since not many change engine oil at 5k, using a good synthetic that have extended oil drain interval is the best bet. In addition, some synthetics flow better during engine startup ( e.g. 5wXX or 0wXX vs mineral 15wXX or 20wXX ) and more shear stable. If the right kind is used, e.g. 5w30, it can gives better FC.
SAE 15w - 40 or 20w - 50 are good for local driving. High-end engine oils (eg. 5w - 40) are for extremely cold climate and performance races and have shorter lifespan. If you want to use mineral oils, SAE 40 will be good. The major differences between mineral oils and synthetic are that the former has a fixed viscosity at a given temperature and it's viscosity will change over different temperatures while the latter has a variable viscosity which means it's consistency will remain the same at different (but reasonable) operating temperatures.
Another difference is that sythetic oils are usually full of additives (eg. to reduce molecular friction, adherence to surfaces, etc.), hence the price.
Depending on how frequent and how hard you drive, the choice will be different technically but still economically driven.
There was a time, out of interest, I was trying out the various type of semi-syn and fully syn engine oil for my US-brand-but-Korean-Origin car. I send used engine oil sample (for UOA) to US for testing of wear levels and if the engine oil is exhausted. The conclusion, my car and usage pattern requires me to use a really good synthetic engine oil.
IIRC, i've read in some car forums, the service agent, tells stuffs like the engine already run-in at the factory or it already comes with synthetic engine oil. I see the odometer showing that few hundred km, with so little mileage, does that considered to be run-in also bearing in mind that expensive petrol needs to run the engine ?
I would say different makes and usage pattern determines the kind of engine oil. Good maintenance is kind of like insurance because one won't know if it is possible to sell in a few years.
A car is a tool for me, to go from A to B. As such I care about it's reliability.
But I don't look after my car as if it is my darling, that I wash it weekly or polish it every few months.
The dealer (of my car) offers mineral oil and synthetic oil for the service packages, so are many other workshops like comfort delgro. If your question implies mineral oil is a "not caring" choice, then the package should not be offered in the first place, and further more, the dealer and workshop would be really nasty to sell something that ruins your car. But then, I don't believe they want to do something like that.
The price of the two packages differ by $100. If the mineral oil does it job, why not?
Thanks for all the constructive feedback and information.
I always thought high engine rev is stressful to the engine and didn't realise start-stop driving is also stressful. True, even if we take the expressway we may still end up in such situation! While I can avoid high revs most of the time, I cannot avoid start-stop.
One workshop also mentioned to me that, if I drive only at low speed (I presume the same as low revs), therre will be carbon accumulated in the system which will reduce engine/exhaust's efficiency. As such suggest to drive at high speed (high rev) once in a while so that the heat will burn off these carbon. Did you guys hear something like this before?
Frankly I'd go for a mid range synthetic oil for a number of reasons. Firstly Singapore is quite a warm driving environment so under bonnet temperatures will tend to be on the high side (a bit like here in Australia in summer), second the friction modifiers in synthetic oils do tend to do a better job of protecting petrol (and diesel) engines as the molecules don't oxidise as easly and are more stable in low and high operating temperatures.
One thing, once you decide on mineral or synthetic do not swap back and forth as cross contamination opens up a whole can of issues with possible lack of lubrication being a very real concern. If going from a mineral to synthetic oil you should drain the old oil, put a new filter in, run the engine for a few hundred KM, drain the oil and install a new filter and oil. This will ensure that the "new" oil is pretty much uncontaminated. Using an oil addative such as Nulon once the engine hits about 50,000km will help prolong engine life regardless of oil type.
Two synthetics I can recommend entirely are Mobil 1 and Castrol Magnatec oils both of which are used extensively in the racing and really do what's written on the tin as it were.
Finally, never run synthetics in a rotissary (Mazda Rotary) as Mazda do not recommend it. :devil: