Hi all,

I am trying to decide what engine oil to go with for my 4.7. People I have talked to who used to race say that the thicker the better (20W50 as opposed to 5W30). Articles I have read seem to support that to some extent and it seems to make sense to me as well, however, some info I have read on the 4.7 which I found somewhere in this forum states that the engine is clearanced for 5W30.

Is 5W30 good enough in everyones opinion, or are others using something else?

Also, in terms of synthetic. When switching to synthetic, is it just a matter of draining the mineral oil and putting in the synthetic, or should a flush be done first? Any recommendations on brand and weight of synthetic?

Thanks!
Rob

 

20-50 is way to thick for this engine. If you live in a climate that see's winter. It would be silly to use an oil that thick.

5w-30 is fine... Thats what the manufacturer wants you to use, I would use it.

I use Mobil1 EP, and change my oil every october. Winds up being around 12,000 miles per oil change. We have always done this with all our cars, they have ran great into the 200k mile range, and on the few vehicles where I did pull the valve covers, they have been clean as a whistle.

Plus, it only cost me around $40 per car, and I only have to crawl under them once a year.

You should be able to switch right over to synthetic from mineral oil, without a problem. UNLESS your engine is high miles, and in that case, sometimes synthetic oil may reveal some sort of leak due to its cleaning agents. I switched 3 of my cars to Mobil 1 after there factory fill, and one car at 33,000 miles. None of them had any problem.

Make sure you stick with a REAL synthetic oil, that is PAO based, like Mobil 1 EP, or Amsoil if you plan on running extended drains.

 

I run amsoil 5w-30 full synthetic and change it every 6000 miles...I wouldn't run anything thicker...10w-30...unless you have 100 degree days for extended periods.

 

I agree about the 20W50 and mentioned it more for an example. I figure it's typically used more in racing applications in engines with looser clearances, but I was wondering if going to at least a 5W40 or 10W30 at most would be better. I will switch to synthetic though. Thanks for the advice!

Rob

 

10w30 is only heavier at startup compared to 5w30. Why would you want that? Even given 120F outdoor temps I would choose the 5w30.

 

i stick with the factory recomemeded oil, i go to sh!tty lube and use there junk every 4500 miles or so, truck now has 90000 miles on it with no issues, and i still snot the crap out of it as much as i can. i dont beleive in that other crap

 

20w 50 way to thick trust me i found out that i put it in my truck and ended up with a valve tap. thank god if drained it out and put 10w30 back in. i would run 5w30 but i feel safer with the 10w30 since thats what the dealership had put in it. anything over 10w30 is overkill and u will problem end up with more problems. racing motors need thicker oil because of everything is bigger and more space to allow more horses 4.7 are good engine but like blown showed me the OHC (overhead cams) in our trucks needs thin oil to run great. when i changed back to 10w30 my truck got up and go a lot faster.

 

I do 10w30 and it seems to be fine. We do have 100+ degree days quite often here in Phx though!