what your owner's manual says. Wouldn't that be kind of an oxymoron. Seriously, it would be COMMON knowledge if the majority of people had access to an F-150 manual and actually read it. BTW, our manuals are NOT infallible.

Here's why I asked if 10W-30 would be OK in SA. The local Costco carries Mobil1, but only in 10W-30, not 5W-30. It is about 20-30% cheaper.

I was asking because I am a NEW F-150 owner. I was an auto appraiser for 3 years and am familiar with many different vehicles. However, I am NOT an expert on any particular vehicle. That's why I don't mind asking what was apparently a stupid question. Regardless, no one actually answered the question.

Simple yes or no and I'm going with YES it is OK to use 10W-30 Mobil1 in San Antonio year round.

P.S. Dennis - do you make all your decisions based on what you read or do you also pull from your's and other's experiences? Just curious.

 

Frank, that sounds like logical, sound advise to me.

However, I would think 10w30 would be fine. It's been published that Ford went to lighter viscosities for fuel economy. However, I personaly would run what the owners manual recommends. Call it conservitive or a comfort level, it just feels right.

 

LOL... Not sure if I prefer being older than dirt or older than sin...

All I do is quote the owner's manual. Sorry if I come across as an Owner's Manual Thumping Fordnick.

 

GO WITH 5W-30. IT'S CLOSER TO FACTORY SPECS AND IT WONT HURT A THING. I RUN 5W-30 ALL YEAR ROUND. OH YEAH, YOU'LL GET BETTER GAS MILAGE TOO!

 

Actually, I read the manuals, warranty, and maintenance guides of every vehicle I buy from cover to cover. The more I know about what Ford requires, the better off I am when I have a problem that needs warranty work. I learned the hard way when I got my first new car when I was in high school back in 1970.

Also after having retired from running a multi-million dollar business for quite a while and NEVER having lost a liability claim or labor dispute against me, I'm pretty careful about how I state things. I am also acutely aware of liability issues because among other things, I teach people how to operate their boats in big seas (having been on the water and piloting boats since I was 5 years old).

Yes, I draw both from what I read and from what others tell me and I make an educated choice if the two don't jive. However, if one is a risk for any reason, I will give more weight to the other.

You will never see me advising anybody to actually use any fluids that are not Ford approved according to the manuals BECAUSE I am not an expert in the lubrication field or engine design and engineering and I would not want to be responsible for somebody voiding their warranty or wrecking their engine/vehicle.

If you had asked what the manual spec'd for your truck, I would have said for a '98 model, 5W-30 oil is what Ford calls for. I would also tell you that Ford has also approved 5W-20 for use in your engine, but it's use is optional in your year engine. 5W-20 is required in the '01 and newer engines.

BTW, this is an old argument with me quoting the Owner's Manual and others saying they know better. Nothing new except that now I tell people that ultimately, it's up to them what they use. Just don't be surprised or upset if something happens because you thought you knew better.

P.S. Now, aren't you glad you asked me?

P.P.S. I tend to be conservative when dealing with my vehicles. Boats are a whole other story, though.

 

I'm sorry if I came across as "knowing better". That was not my intention.

I grew up being taught by my father (not always a good thing), that the weight of the oil used in a vehicle was a factor of the manufacturer recommendations as well as the climate in which the vehicle would be in operation. Being in San Antonio, he "always" used 10W-40 vs. 10W-30 and so on (especially in the summer months). With newer engines I am not so sure that his theory still jives. Hence my posting the question on this board.

Bottom line is that I'm trying to get Mobil1 from Costco at a cheaper price, but they only carry 10W-30.

P.S. My previous P.S. comment was based on your previous answer, "Common knowledge is to use what the Owner's Manual says." That's all. I was hoping to get some more info from people. Knowing more of your background, I would think you have more information than just referring me to the manual.

P.S.S. I believe that the information shared on this board is beyond common knowledge - that is why I come here. My wife is amazed at how I'm able to troubleshoot using information on here. I have probably saved over $1000 via my F150online education.

 

I would say since you are going to be using mobil 1 you can use the 10w30 no problem. This stuff will pour better than a conventional 5w30 in cold weather!!

Good Luck with your truck

 

So where does one find 5w-20 at a reasonable price ?
Maybe I should go to synthetic given the cost of the stuff.
I was only planning to use synthetic in the summer, where it is over 100 degress f, and i will be pulling a trailer.
I live in a fairly large community, and man is the stuff pricey(5w-20).
Consequently, I have been using 10-30 for the vehicles first
two oil changes(2001 EB Espy 4x2).

Any and all thoughts appreciated.

 

It's funny how this stuff gets out of hand. But anyways, talking to Mike Troyer many moons ago, my local mechanic, and a retired engine builder, they all agree that 5W30 should only be used in the winter when temps are below 30. Ford doesn't recommend what is best for your engine. I personally have noticed that 10W30 is a little thicker when hot than 5W30. There must be some wiggle room when they class a certain weight of oil. You want a little more cushion in summer and when the engine is at operating temperature. Synthetics do flow better when temps are under 30, so that would be the only reason why I would run them if you live up north. Thank God it doesn't stay cold here in GA. So I run 10W30 year round.

 

Hi Dennis. I'd rather be older than dirt. At least then you would have seniority.

And Jeff, B.S.!!!! You said exactly what was on your mind and that is your choice. Just know that you kind of come across rather crudely to your brethern F 150 owners.

 

I've only posted 25 times and I already come across rather crudely.

You are right, I need to work on my wording. I have been told that I come across harsh in e-conversations (e-mail, message boards, etc.). That's the problem with typing versus talking - if you have a dry sense of humor there is no way to detect it in type. Oh well.

If ya'll knew me, you'd know I don't mean anything by some of my "harsh" or "crude" statements. Eduk8er was right in saying I said what was on my mind, but I could have tried a more pleasant tone while delivering the same message.

Honestly, I do appreciate learning from all of you even if I don't completely agree with all of you. Isn't that what life is about?

 

I also switched to Mobil1 synthetic....I was using 5w20 in my 2001 Screw but changed to 0w30 at 10,000 miles...no more engine clatter at start up....

 

It amazes me that people think they know better than the recomendations of company who employees hundreds of engineers with countless years of experience building internal combustion engines.

 

I see the red Motorcraft 5W-20 synthetic blend at a couple of stores in my area. They're running about $1.75 a qt. If I can find it in my tiny town, I'm sure it's available in larger cities.

I'm sure you'll be seeing more brands of 5W-20 in the coming months. Afterall, how can an oil manufacturer ignore Ford? It wasn't all that long ago that it was difficult to find 5W-30. Now everybody makes 5W-30.

I'll bet that Mobil comes out with a 5W-20 that satisfies Ford's specs before the year is out. Maybe as soon as this summer.

 

I think most folks are speaking from years, if not decades of personal experiences with countless products and it would be an insult to their intelligence to say they don't know what the hell they are talking about. On the other hand, those corporate boys can charm you out of your life savings and talk you into buying a rattlesnake for your 3 year old as a pet. I'll put my money on good ole' hands on experiences anytime.