So did these guys end up using 5w-30 or what? I have some 5w-30 Castrol GTX that I'm contemplating using with a motorcraft filter. That oil has got to thin out real quick when its 99* outside here in South Florida.

Cory

 

Been using 5w-30 & the Motorcraft filter on my 04. Zero problems.

 

wow, talk about digging up an old thread....4.5 yrs old...I think that's a record in this Forum


use the 5w20. I've used it in Texas (100+F) and I know plenty of others who do as well. You are just costing yourself fuel economy by using a thicker oil with a higher viscosity


btw, Motorcraft is good stuff at a great price

 

I been really trying to dig up some specs. Because once I make a decision on an oil, I would like to stick to it. I have 68,000 miles on the truck ( new to me truck, I bought it with 67,XXX miles)...and I live in a hot climate, so I'm looking for the best protection and fuel economy I can get.

Would having higher mileage at this point be a reason for me to make the move to 5w-30? I know some people go to a slightly thicker oil when they have more miles. I'm not really debating, I'm just weighing the pro's and con's so I can make a good decision. Aside from the fact that I can't seem to find 5w-20 oil that easily.

 

Mobile 1 5w20 and K&N Filters.

 

walmart all the way man.

motorcraft 5w20 semi-sythetic. same stuff the dealership will use, but cheaper. same thing with the oil filter

FL-820s oil filter for the 5.4 and 4.6 (unless canada motor)

 

Motocraft semi syn 5/20 and Motorcraft filters almost always in stock at Wallys World. Lot cheaper than the dealer, The filter is key as it has a very good anti back drain valve. IMO

 

Anyone use amsoil ?? i use it in my wifes car and my old truck and in her car you can notice a cooler running temp and few extra mpg on hwy..

 

I uses 5-20 mobil one oil and motorcraft oil filter. i m happy with this set up.

YOMAN!
'04 Screw 5.4

 

I am using Motorcraft 5-20 and motorcraft filters consistently.

 

The thinner oil, Motorcraft 5W20, makes the engine last longer, much longer life. You will find gasket leaks earlier : valve cover , etc. The motorcraft filter is one of the best for the money. Together they make the best protection for the money.

 

same stuff that comes in it.

 

For great protection use Mobil-1 5w-20 & a Mobil-1 High Efficiency Oil Filter part # M1-210.......

 

I uses 5-20 mobil one oil and motorcraft oil filter.

 

'what oil' threads are always a guaranteed argument starter, but I'm encouraged to see the majority going with the factory recommendation of 5W20. To understand engine oil a little better, I'll list a few facts: the use of lower-vis oil in new engines has been shown to the satisfaction of the manufacturers (against very determined resistance over many years) to provide better service. In fact, the leading cause of OHC engine cam failures is the use of inorrect higher-vis oil (Motor magazine). Thicker does not necessarily equal better in an engine made for the lower-vis oil. Racing engines have used higher-vis oil for two reasons - they do not have to (usually) start in cold weather, and they are clearanced for the oil. The key to extreme temperature (both high and low) operation is simply the oil temperature at start. Any oil with the high number of '20' (20W, 10W20 or 5W20) will equal 20W when the engine is fully warmed. The need for the lower number is to provide better flow when the oil is cold. The critical difference is, a straight 20W will not provide engine protection on a cold start. So, to the question of whether to use an oil with a higher top number in a warm climate, you would not. In a truly hot climate with no starts with the oil at 50F or less, you could theoretically use a straight 20W. However, even in the high desert overnight temps can drop to nearly freezing, so a multi-vis would still be indicated. As to what to use in a used vehicle, it may depend on what has been used in it previously. If the records do not exist, I would use the recommended oil. If excessive consumption occurs, it might indicate the incorrect oil had been used resulting in possible accelerated engine wear and excessive clearances. In that case you would have to use a higher vis oil. As to dealers refusing to use the recommended oil, see the part about 'resistance' above. I used to think that way but learned the hard way that use of 'racing oil' or other high-vis oil in modern stock engines is a recipe for disaster. My 2007 F-150 with 4.2L V6 gets Motorcraft syn-blend 5/20. I like this oil so much that I have switched to it in my two SUVs with DOHC/4-valve engines (5W30 for them to meet the factory recommendation). I was using Mobil-1 in them, but since we are both retired and don't drive as much, I use the Motorcraft and change at four months instead of six. So whether you use Motorcraft, Mobil-1, Amsoil or whatever, just be sure to use the manufacturer's recommended vis.
There is just one more thing - a straight-vis oil is better than a multi-vis oil in one important way - it's all oil. A multi-vis oil contains a high proportion of molecules designed to grow with heat, providing the viscosity increase needed. These molecules are not necessarily lubricants, so you can see that the multi-vis oil is deficient in a way. The blenders make up for this deficiency to some degree with additive packages. This is sort of a moot point, because most of us cannot get away with using a straight-grade oil. Just be sure to not let the multi-vis go too long, because over time it can degrade to the base oil number - a 5W20 becomes a 5W. This effect is more pronounced as the difference between the two numbers increases (more modifiers added to the base oil), so a 5W30 is more likely to degrade than a 5W20. If you plan to use engine oil for more than six months/7500 miles, you would be well advised to start using one of the oil testing services. I will be happy to listen to any arguments to the contrary to any of the above points. This is knowledge I have accumulated over time, and science does change over time. Like the idea that 'thicker is better', some 'knowledge' simply gets outdated as engineering and science improves, and mine is no exception. I will say that since I 'wised-up' and started using the correct oils in my new vehicles in 1990, I have had no engine failures or oil consumption.