Been busier than the confessional at a Catholic prositute meeting lately, and my oil was getting overdue to be changed. The wife took it to Jiffy Lube last night when she went to the store. When they changed the oil, first of all, they put in 5W-20 instead of the 5W-30 I usually use, and they put in Synthetic Blend instead of regular oil (and charged her 5 bucks for it and never asked first).

My questions are these:

1) I am concerned with the high 90+ temps we are predicted to have, coupled with the fact I will be towing my bass boat a couple of hours this weekend, could I damage my motor with the lower viscosity oil? For background, I have a 98 with the 5.4L and 107,000 miles.

2) I thought I read somewhere that going to a synthetic on an older motor could be bad for it.

Thanks in advance for any answers.

Dan

 

i wouldn't worry about the 5W-20. ford is recommending that weight for your engine on all of the new F150s and there is no difference in the engine specifications or tolerances on the new engines from yours. i've been using 5W-20 in mine for 30M miles and it is doing just fine. i've been towing also. 4 hours at a time.

also, you can switch back and forth between dino and synthetic with no ill effects. you can even mix them. i've done it for years on a variety of engines and manufacturers with no problems whatsoever. ran one VW 4 cylinder for 250M miles that way.

rapid oil change pulled the same "synthetic blend without asking" thing on me a couple of months ago. i just said that i didn't ask for it and that i was only going to pay the regular amount.

 

Don't sweat the thinner oil being in there. So far, oil analysis is showing that the 5w20s are doing a pretty good job. If you are worried, I'd give it a shot for 3,000, and then change. No sense in wasting good oil!

Ford has released a TSB (a while ago now) that approved the use of 5w20 in these engines to older model years. I'm running 5w20 in both my 97 and 99 now. So, that isn't a concern.


As far as being charged for a Syn Blend, I can't say I'm surprised. All 5w20 oils being sold right now over the counter are a Group II/Group II+/Group III blend. Group III base oils are considered by the oil manufacturers to be a synthetic oil, when they are really just highly refined dino. Motocraft calls its 5w20 a "syn blend" on the label, but nobody else does, yet anyways. According to current definitions, calling these oils a syn blend is correct, although they are really just a high quality dino oil. They will not cause any leaks in a higher mileage engine. I put the motorcraft into my '97 when it had 160,000 miles on it - no leaks.

In any event, if you go to the store, you will see most 5w20's are priced higher than the same brand dino in 5w30, for example. Generally about 1.80 a qt. Thus Jiffy Lube is finding a way to charge extra for the premium oil. Not surprising.

What is surprising is that they used a grade not originally recommended without your consent. Its fine, just odd they went that route. Someone must have pounded their heads that they make more money pumping 5w20 in cars that can use it!

Short story, don't worry.

 

Check out this analysis of a F250 V10:

5w20 Oil Analysis

I would say don't worry, and you will probably see better mpg's to boot.

Not to mention that you have a semi-syn in there over a conventional. The syn portion should give better protection during high heat and towing, as it won't thin as much.

Hope this helps

 

Dan, I agree, not a problem.

Keep in mind that the opinion 5w-20 is too thin, is part of a hair splitting debate. The 5w-20 is made from a better base stock than the 5w-30 you wanted, so weight issue aside it is a better quality oil that meets higher specifications.

Though I agree the thinner oil may not be a 'best' choice if you do mostly towing, the oil analysis of late have been very good in trucks that have at least done some towing.

 

i have a question about oil..... i had a similar situation happen but instead of going from 5w30 to 5w20 this garage put in 10w30 ..will it hurt to go back to 5w30 or should i now just go with the 10w30 from here on out......i have 66,000 on my truck

 

NO dont stay with the 10w30....go back to the 5w oil. Its better protection with the Triton engines

 

You will have absolutely no problem with the oil in there, but if you want to spend the time and get your $5.00 back, you can go in and complain and demand they change the oil to the specified 5w-30 and ask for your $5.00 upcharge. To be honest, if they only charged $5.00, their profit wasn't any greater than if they went with 5w-30, so it was to no advantage for Jiffy Lube to upsale your wife. If it were me, the $5.00 isn't worth the extra time and the oil will perform just fine.