My friend has a 2000 F-150 with about 120,000 miles on it, and wondered if he could make the change to a full-synthetic product. I suggested that the vehicle may be too old to make that change.

What do you guys think ?

Thanks...............

 

There's no reason it's too late to switch. Most "synthetic" oil in the US is actually Group III base stocks. Group III is not actually man made, but just highly refined dino. The "synthetic" term refers to the performance in the US.
There are actually many companies that admit their synthetics contain as many seal conditioners as their high mileage oils, making conventional high mileage oils obsolete. In some cases we do see some consumption during the first run of "synthetic" but after that it usually levels off.
I wouldn't be doing my job if I didn't ask if your friend is also going to change his oil change interval along with the switch? Most good synthetics have the TBN to go well over 5000 miles between changes, as long as fuel dilution isn't too high. Conventional may suit his needs just fine and be cheaper if short OCIs are going to be used.
In short, it's never too late to change, but synthetic isn't always better on a cost basis. Conventional can protect just as well in some cases.

 

I've heard of a few problems where higher mileage engines will start leaking once its been introduced to synthetic. It's like putting thinner oil in when its about time for some high mileage stuff... I have 52k on my 03' and was also wondering about the synthetic swap myself.

 

Synthetic isn't "thinner" than conventional oils. The viscosity levels are the same for a 5w20 syn and a 5w20 conventional. Where the main difference is, is that most synthetics have higher calcium and other detergent packages that can slowly clean sludge that has accumulated and block bad seals. They counteract these effects with quality seal conditioners. A bad seal is a bad seal.

 

Great info! Thanks for clearing those rumors up for me. I think I'll be going synthetic next oil change.

 

"There's no reason it's too late to switch..."

Thanks so much for the great input. It sounds very reasonable and I will pass this on to my friend.

Generally, I'm a big fan of using synthetic oil myself in the new vehicles I have purchased, but I was unaware of the potential ramifications in older vehicles.


Dave