209trucker

Wondering what everyone else thinks. I know, typically you replace your fluids with what the manufacturer requires. But my buddy was telling me how he's changing It all, motor oil and tranny fluid and gear oil. And while he sounded excited, I stayed quiet, because I never really believed synthetic fluids would do much good for a stock Toyota Tacoma with a manual trans and 4x4 and I didn't want to strike up an argument. I know it's said that you can extend your oil change intervals, but they still recommend oil changes as you would with standard petro oil to filter the dirt out.... So what's the difference with the motor oil? Or anything else for that matter

NE frmhnd

Mainly, the synthetic is a lot "slicker", lubricates better, and depending on he vehicle, you may be able to measure or maybe even see the better fuel mileage it should get you.
Some synchronizers (Chrysler A833 comes to mind) don't like synthetics, it's too slick and the synchro's don't work right because of it.

Cummins610

If you are not in a climate that operates in extreme cold, or are interested in extended drain intervals then synthetic is a waste, in my opinion

SIXSLUG

I run synthetics in the driveline and straight 15W-40 in the engine with change intervals at 5000 miles.

I chose to run synthetic in the driveline for cooler operating temps and extended maintenance. Without a fancy double filter set up for the engine, I just keep it simple and change it out when needed.

It's easy to get caught up in all the hype surrounding "performance", I just would rather have a little extra jingle in my pocket!

torquefan

I started using synthetic in the engine because it works better in extreme temperatures. It flows better when very cold, and it handles higher temperatures before breaking down. I also like to use 5W40 year round instead of 15W40, because I can't always plug in. Never really been too interested in extended drain intervals.

Bark

Like others have said about the cold.
Up here if your vehicle has been sitting out in 0 degrees over night you can really (and I mean really) tell the difference between synth and reg oil.
The engine turns over so much faster with the synth, its easier to put in gear and the vehicle can actually roll without the differential lube holding it back.

In warmer climates I have been doing what SIXSLUG does and use synth only in my drive line.

Just my opinion which as normal has no scientific backing.

Fiftygrit

Synthetic fluids do not break down as fast under excess heat, if you tow lots and on the heavy side you cant beat them, motor oil every 5k mile 15-40 is fine, but good trany and diff oil may save you in the long run, thats what I get from reading about guys with high mileage trucks that haul for a living.

gorms

I finally switched the last fluid in the truck to synthetic this winter (engine oil 5w40) and don't know why I didn't do it sooner. Well I do know why, it's more $$$. But it seems to run more consistent after 7k miles, and cold starts still aren't an issue so in the long run it may even out on price. Already have been running synthetic in axles/trans/power steering with good results, and as stated above especially when working in extreme temperatures. If it's 65 and sunny all year then probably has little advantage.

SIXSLUG

I agree with what the guys are saying about synthetics in the colder climates definitely.

I should mention I plug my truck in from the first frost til the daffodils break ground, which is right around now, so I don't have the flow issues.