Mobil High Mileage or Motorcraft Synthetic Blend

[shadowless127]

134K miles. Had been using conventional/bulk oil until last oil change the guy showed me a bit of gunk build up so I switched to Mobil High Mileage and noticed some improvments. Now it's time to once again do an oil change and I need to know if I should stick with the mobil high mileage or switch to motorcraft syn blend (the place I go to has both for the same price).

If you have other suggestions for what oil to use let me know, I can always pick up my own oil and filter and have the repair shot 2 doors down from my office do my oil change while I'm working.

 

[mr_valingo]

Dump a can of seafoam in and run i for a few miles then change back to the motorcraft

 

[Maniak]

I ran Mobile 1 for most of the life of the orig. motor on our '92 (4.0 ohv motor) At 355k miles it had no sludge build up or scoring on the cyl walls. It was rebuilt due to a head crack and a dinged valve thanks in part to a spark plug that came apart somewhere in the mid 200k range, but I drove it another 100k+ miles after that.

Using Mobile 1 and a Wix Filter (51515 in my case) I would change the oil every 7k to 10k (8k average).

Our '06 mustang which has the 4.0 sohc like the explorer, only newer has only had synthetic and blend in it.

For the first 36k it was the motorcraft blend (at the dealer). Since then it has only had Mobile 1 and Mag 1 synthetic (mostly mag 1). It was getting Motorcraft filters when it got the changes at the dealer but since then it has been using the Wix oil filter. Blend oil changes were done right at 3000 and the synthetic oil changes have been happening at 6k to 9k (normally around 8k miles). So far we see no signs of sludge in the motor at we are coming up on 225k miles. I'd go longer on the oil but the car is driven 4+ miles on dirt, every day and there is quite a bit of silt/sand/dirt in the air here.

So, my thinking is to use Synthetic oil and a good filter and change it every 8k or so. If you're worried the oil is getting too dirty get a used oil analysis done after 6k or so on synthetic and they will tell you if it is getting too dirty.

Heck, you could do that with the blend if you want. That way you will know how often you really need to change your oil.

~Mark

 

[SoNic67]

For peace of mind if you go extended intervals with synthetic oil, you should use a long-interval, synthetic media filter.
Otherwise, at some 5-6k you might be in by-pass already or have the media punctured.

 

[swshawaii]

(Valvoline SynPower)

http://www.napaonline.com/Savings/CurrentPromotions/OilChange

 

[Flash]

Dump a can of seafoam in and run i for a few miles then change back to the motorcraft

In this case where the oil has just started to sludge I reckon it would be safe to use Seafoam or a similar crank flush as the build up won't be very big.

I'm guessing that something called High Mileage would be pretty thick and wouldn't have much if any detergent in it, seems to me that would be counter intuitive for an engine that's starting to sludge up.

Thick oil isn't good for the SOHC engine because of the delay in building oil pressure for the timing chain tensioners.
If you're in a cold area the chain guides might thrash themselves to death before you get enough oil pressure to shut them up.

I'd be looking into the cause of this sludge build up, it might be time to improve the quality of the oil you're using.

 

[koda2000]

high-milage oils are not thicker that regular oil of the same weight. they just contain additives to soften old stiff oil seals so they work better.

 

[Flash]

high-milage oils are not thicker that regular oil of the same weight. they just contain additives to soften old stiff oil seals so they work better.

Key words there are "same weight."
Obviously it's not going to be thicker than another oil of the same weight, I just thought that "High Milage" oil would be a thicker oil.

Unless I'm reading that wrong; I took that to mean it was for a high mileage engine with looser tolerances.