Black96Max

iTrader: (1)

I just took ownership of a 97 maxima 5 speed with 190K on it. It has been using regular oil its whole life and now im wondering if i should change to synthetic or a high mileage oil? i plan on using this vechile everyday and want it to last as long as possible. Any other suggestions would be greatly appreciated.

JD05

I would keep using the same oil you heard the saying if its not broke don't fix it. Is it burning oil? If so try a thicker oil.By changing to synthetic might damage it because synthetic was never used. High milage oil is thicker if it isn't burning oil use the same.Or if you want change the type of oil do the high mileage oil not synthetic.

talkinghorse

iTrader: (121)

High mileage oils typically contain more robust additive packages to reduce wear, lessen volatility, control sludge and to condition seals.

If the engine is in sound mechanical condition, has been well maintained and is not sludged from previous neglect/mechanical problems, switching to a high quality synthetic oil will not cause any "damage".

High mileage oil is not thicker...it is offered in the same viscosities as regular formulations

Some of the high mileage oils, such as those offered by Valvoline, are in fact synthetic based or synthetic blends.

If you do decide to go with either a synthetic or high mileage oil, I recommend staying conservative with drain intervals until you get a good feel as to how it does in your engine.

cdmapro

others will disagree, but my advice is to stick with conventional oil or go to a high mileage conventional. both will be syn blends anyway. my experience is that fully synthetic oils will indeed "cause" leaks and probably valve train noise. on an engine with 190k you have nothing to gain by putting a synthetic oil in it. I have many years and thousands of miles of oil analyses to back up that statement.

Bobo

I recommend you run 2 auto-rx trials to clean out your engine internals, reduce sludge buildup, rejuvenate seals and minimize the risk of any leaks if you in fact switch to synthetic.

Go to auto-rx.com

I used this product about 20,000 miles ago and following my most recent oil change I began to use it on a maintenance basis by adding 4 ounces to the oil.

I highly endorse this product, as do many members of bobistheoilguy.com (BITOG).

Failing that, I would be inclined to use a high-mileage oil and would stay away from an engine flush at a lube joint.

Atimaxx

I agree and many oil experts will agree too with what was stated here. There is no benefit to switching to synthetic at this point. There may be deposits/sludge built up given the mileage and full synthetic oil could loosen them up and then you will have new leaks + possibly other headaches. Keep with the high mileage oil and a quality filter (note: NOT Fram) you will be just fine. I always use Mobil 1 filters or Purolator Gold.