I just had my oil changed and a friend of mine recommended 5w30 instead of the recommended 5w20 for the hot Georgia summer. He said the thicker oil will also help with the valve tapping I heard at idle. He was right! No more valve tapping, and it runs like a champ.

Pennzoil 5w30

 

Anyone know if this will hurt the engine?? I ask because I purchased 3 cases of the Mobil 1 (full synth) 5w30 by mistake for my '05 Mustang - not realizing it called for the 5w20???

 

the 5w30 will be fine

 

Thanks 390 - the "oil debate" is such a heated topic - you never know what to believe. I didn't think the 5w-30w would hurt it - good to know I can use it!

 

You might want to consult the warranty guide. The thicker oil may void the engine warranty.

 

Yeah - I know what you are talking about.......just curious - even if I had an engine issue (which I seriously doubt) do you really think my dealer is sophisticated enough to test my oil??? Is that a "normal" practice for a dealer to perform whenever an engine component failure comes in under warranty? Seems they be more interested in determining: 1) that the engine had oil in it and, 2) it had been changed on a regular basis (per maintenance schedule)??

 

I agree with you guys on the 5W30. That has been all I have used in my truck since the very first oil change. At the first oil change, I switched over to Mobil 1 Full Synthetic 5W30 and I have not had any problems. I currently have 27,590 miles on my '04 SCREW (no motor problems) and I too, live in the heat of South Georgia.

 

I still find it strange to hear about heat from Georgia. Tomorrow it's supposed to be 109 with clouds and high humidity. Nice day.
I was just washing one of my cars, and noticed that while it is only supposed to hit 106 today, it was just a tad warmer. 111. Of course it's cooler up near the airport where the area sensor is placed, 900 feet above in the junipers.


By the way, I use the 5-20 Motorcraft, and oddly, also have no problems with my truck.

If you bag a cam phaser, or score a camshaft, trust me, the dealer will do a check on your oil, weight, amount of contaminants, brand, etc.
Costs about 20-30 bucks to have that done, and if you are the loser, they get to keep the 500-1000 bucks the job can cost.
Locally they have a sign stating that they may have your oil analyzed (along with a bunch of other things, on claims). Not unusual, I’ve seen the same sign at Cadillac.
It’s just a response to the M-F law.

No I don't think 5-30 will hurt a dang thing, especially if you use a very good quality semi-synthetic.
It also won't help a dang thing.
No big thing. I just figure shoot the odds while it’s under warranty.
Chris

 

Chris - that's good information about the dealer checking your oil - good to know! I have a riding buddy (m-cycle) who lives in TX and works at SWI (IIRC) where he tests lubricants of all types...he has been testing all the oils/lubricants for over 15 years and his "opinion" is that he uses Mobil 1 Full synth 15W - 50W "red cap" in all of his vehicles....says the newer, lighter oils are just for better mileage and that he does not trust them to protect like the heavier synth. As a matter of fact - I changed the oil in my '04 CBR1000RR to the Mobile 1 20w-50w full synth and it runs about 4 degrees cooler (consistently) and "seems" to run quieter as well......FWIW......

 

I was one of the first people to point out the oil weight recommendation drops neatly corresponded with CAFE rules, environmentalism, etc.

I have been forced to say that the makers of the trucks/cars have a little bit of a clue as to what they need. This was not my first choice of belief…

I changed the oil in my 7.4 to 20w-50 Castrol semi-synthetic at 8000 miles. I had been running the 10w-30 the dealer recommended since first oil change. I keep a detailed log of every mile that goes on the MH, every fill up, everything. A journal really.
Anyway, the mileage dropped precipitously, down from 11-10.8 running at 65+ loaded, without tow vehicle, to 9.8-10.2. No other changes. This is on five trips, scattered across the year, two oil changes.
So I went back to 10w-30 having noticed no improvement plus much higher oil pressure. 40 lbs at idle up to 50-55 at idle. After going back to 10w-30 my gas mileage surged back up to 10.7-11.1. With tow it had dropped to 9+, now it's back to 10+.

After years of the prevalence of the lighter oil, I am seeing cars locally with 250-300k on the factory rings/bearings/cams that have been run on the light weight oils.
I also always used the recommended weights in our fleet vehicles, Jeep Grand and a flock of Metro/Swift cars. Never had any oil problems.

The old Grand hit 262k never used a drop of oil. Lost exhaust manifolds, idler pulley, transmissions, etc. but never any internal engine problems with 10w-30 oil. We sold it, running great, just looking a little on the tired side.
It was thrashed every day of its life. That's in high altitude with high and low temperatures.
It made upwards of a thousand trips through the Cajon pass in five years. It got a little over 50k each year. I would like to say the oil was changed every 3k. But that would be wrong...

We didn't keep the Metros that long; they were run on mostly 10W-30, the last ones on 5w-30. Never had a valve cover off any of them.
Got one left in the family, it has 190k+ on it now, still doesn't use oil.

So as much as I was always loyal to thick oil, I think I am gonna go with the recommendations from the guys who build, and warranty the truck.
Chris