OK, this weekend I decided to change the oil in my two work vehicles. They are a '95 Aerostar cargo van w/4.0, (160,000 miles), and a '96 Ford Ranger 3.0/4x4 (135,000miles). I have ALWAYS used Castrol GTX in all my vehicles. For some reason this time I decided to switch to Castrol Syntec. The next day I was talking to a guy about engine oils etc. and he claims that it is never wise to switch to a synthetic blend of oil if the vehicle wasn't using it in the pashttps://www.ford-trucks.com/forums/newthread.php?do=newthread&f=35#
https://www.ford-trucks.com/forums/n...wthread&f=35#t. He claims that the viscosity is less in synthetics and I'm sure to get leaks from switching this late in the game. Is this a possibility? If so, I will drag my butt out there bright and early in the morning and change right back to Castrol GTX. Am I really in jeopardy of doing some seal damage by switching? Thanks in adcance.

 

I have also heard the same thing. Don't know if its true though. Maybe someone else here has expeirenced it.

 

Synthetics will not cause leaks, they may however leak a bit more than a conventional oil in a motor that was already leaking. GTX is a good oil and you should get your money out of the more expensive Syntec since you already changed it, but I would go back to GTX after that.

 

I thought that the additives in the synthetics were supposed to help with minor leaks (not anything major). They pretty much all say that they help 'revitalize' seals and such, but I have also read elsewhere on here that people have had problems with putting synthetics in high mileage engines.

 

I bought my ranger in 2001, 4.0L, 4x4 Xlt. I broke it in using regular oil until I hit 10K, then I switched to Mobil 1, and the higher viscosity type, 5W-50, I live in the desert and the heat is hard on cars, and me. So far no problems, no leaks and actually the engine seems to run quieter. Might be my hearing too, never can tell about these things, but it seems to be working well with no problems. My truck isn't high mileage, I thought that using synthetics would make the engine last longer, I don't intend to buy another one anytime soon. I want to drive this until the wheels fall off, or they make a ranger that gets better than thirty miles to the gallon.

 

I bought my ranger in 2001, 4.0L, 4x4 Xlt. I broke it in using regular oil until I hit 10K, then I switched to Mobil 1, and the higher viscosity type, 5W-50, I live in the desert and the heat is hard on cars, and me. So far no problems, no leaks and actually the engine seems to run quieter. Might be my hearing too, never can tell about these things, but it seems to be working well with no problems. My truck isn't high mileage, I thought that using synthetics would make the engine last longer, I don't intend to buy another one anytime soon. I want to drive this until the wheels fall off, or they make a ranger that gets better than thirty miles to the gallon.

 

my ranger is about to break 100k and i was considering to switch her to synthetic since it was getting some miles on her. is it even worth it? or should i just stick to the type i have been using.

 

I just switched a '99 Ranger 3.0 liter with 100,000 mi. with great results. I am a firm believer in synthetic engine oil, trans oil, diff lube, 2 stroke etc., with some caveats. Essentially, if your engine burns oil, don't switch to synthetic. It's just too expensive to burn. Your engine must also have decent oil pressure. The lighter weight of some of the synthetics can lead to "ticking" of hydraulic lifters if the clearances are starting to get wide. In an engine which is in good repair, it should be no problem - with the following cautions. Synthetic oil will disolve a lot of your engine's sludge, so change the filter after about 2000 miles. In really old engines with seals made of old-style composite material, the synthetic oil can disolve some of the carbon, goo and substrate which has become infused into the seal during the years. This can occasionally lead to a bit of seeping at the seal. I have used Amsoil products for about 18 years, with great satisfaction. There are now quite a few manufacurers of synthetic products, though few of them offer the full range which includes filters, engine flush, trans fluid and diff lube. Mobil 1, Royal Purple, Castrol come to mind as reputable manufacturers. I am sure that there are a lot of great products out there.

Brian
'99 Ranger
'63 F100 Unibody

 

i must concer with all the previous statements i too have switched my 98 4.0 L 2WD from conv. to Mobile 1 i live in Idiana( duh) and use the 5W30 couldn't be happier although i too have a question what kind of intervals are you doing changes at i'm still doing 3000 but when i worked a Auto Zone people would come in talking about how they would change every 10K or even more also did everyone change to a differnt filter i'm still using the good ole Fram

 

I just don't understand the synthetics. I've gotten well over 200K on engines by using "regular" motor oil which is much much cheaper. No one here is going to get a half-million miles on a truck, so what's the point in spending all that money on synthetic oils? I'm just not getting it. And yes, synthetics will find every hole they can to leak out of.

 

I use synthetic, Mobil1 specifically, in my Ranger. Started at the first oil change, and every time since.

I use it for one major reason. Here in northern Wisconsin, it gets cold in the winter. REALLY cold. And synthetic just flows better in the cold. My truck starts easier with synthetic when it's bitterly cold, and I've gotta imagine the synthetic does a better job of lubricating the engine on those really cold starts, when the dino oil is still goo, at least for the first few seconds.

Will my truck last longer? Eh, probably not. Everything else will still wear out eventually anyway. But if I can prevent a few jump starts in -20 degree weather, the few bucks extra for synthetic is well worth it!

 

One advantage to Synthetic is that you don't need to change the oil as frequently. From what I've been researching, oil analysis' show that synthetic oil can go over 25k miles, as long as the filter is changed every 3-5k. That is what I've been doing the last 12,000 miles. I just have to add one quart at the filter change to make up for the half a quart that always disapears and the other half quart that is in the old oil filter. I am trying out doing the filter change ever 4k and the oil at 16k I've noticed that after the oil change, the oil on the dipstick looks almost like new. I bought my Ranger with 90k miles on it, and I now have 121k, I started using synthetic on my first oil change, and now am using Mobil 1 15W-50. Being a bit thicker, It seems to work better in my well broken in motor than say a 10W-30 or 40.
Doing it this way, figuring in 1.58 for a good conventional oil, compared to 4.77 for Mobil 1, and a 2.77 Motorcraft Filter it costs me 6.56 more to run Synthetic over that 16k mile period, which for me is a year and a half of driving. Not a huge blow to the wallet.
I agree that it is a waste of money if you change synthetic every time, but if you take advantage of the properties of synthetic (extened oil life,) you can minimize the extra cost of better protection. Synthetic will also not burn in the combustion chamber like dino does, helping to keep the oil cleaner longer in older vehicles.
I also agree with jase71 about it's cold weahter properties as well as it's heat properties. I can use a heavier oil that still flows good in the winter that can withstand the summer heat, therefore not having to switch oils summer and winter. To me that is important as here in the Mid West, it can get down to -20 on the cold winter nights, and up and over 105 in the summer days. The 15W40 I am using will pour at lower temperatures than conventional 5W-30's.
Check this link to learn some facts about different oils.
http://www.vtr.org/maintain/oil-overview.html

 

Needless to say when I started this thread I was hoping to get some very strong opinions that would sway me either way. Although most feedback was insightful, you guys are just to wishy washy on this area....I am going to just stick w/synthetic and see what happens.

 

I've read a few post where some Porsche folks ( I visit there more often) have tried moving to a thinner syn and experienced leaks. Moved back to the thicker vic. and the leak goes away. In my case, I'm sticking with the Porsche factory 0w-40 syn fill. At least while under warranty.

 

I've ran Mobile syn for almost 15k miles no problem in my Boxster. Engines still pulling strong.

My 99 Ranger XLT 2.5l has Mobile 10w-30 syn that has been in it for 2 1/2 years with only 4,000 miles. Not one problem. Well, I did have to add half a quart a few months back.