My car is currently running at 73K miles. I want to switch to synthetic oil but I have been reading different post about people complaining about leakage due to the seals are worn and accustom to regular oil. Even talking with the dealer not that long ago, he even mentioned that I might get a leak due to the mileage of my car. My question is, do you recommend I switch to synthetic or should i just stay with my regular oil? Also, if I do receive leaks, what would be the plan to stop the leaks? Do I switch back? Am I looking at a higher cost to repair? Do I just refill and in time the problem will correct itself? Do I refill, but use the high mileage synthetic instead?

My goal is to get my car on synthetic and not have any issues. I want and plan to have my car for over 10 years.

 

Just guessing but you could try synth blend, then over time switch to more and more synthetic until you're not using any dino oil at all.

 

Just do it. I think you'll be fine. Even though I don't know for sure, these problems may be myths from a long time ago on older vehicles. I'm pretty sure synthetic oil is formulated now to work just fine at anytime/mileage. And besides, 70k miles is not that high. Maaaayybe if your car has 180k I would possibly think twice about switching.
Someone please correct me if I am wrong on this, but I pretty much guarantee your not gonna develope any leaks from switching.

 

my car gets either regular or sythethic blend oil changes-no leaks after almost 165K miles.

 

I like fully synthetic but everyone has different opinions on this.

 

Most "fully synthitic" oils are far from fully synthetic.

I run a true grp V Ester synthetic because I'm OCD. No leaks yet. Transmission has been on a synthetic for over 100,000 miles as well. Engine got synthetic at roughly 3,000 miles.

Those old myths that started in truth around one of the '70s synthetics just won't die. You can switch back and forth as much as you want. Most synthetics are a blend anyway. You won't find a grp IV PAO synthetic without a grp III dino base mixed in. Only if you do a grp V you might have pure synthetic.

 

M1 is not fully synthetic despite the name but it is still a great oil for any street vehicle. Most high end manufactures (MB, Porsche, etc) use it as OEM oil. For the price it is a nice middle ground between a fully synthetic oil where frankly, is excessive in a street vehicle.

 

What about M1 Extended Performance? Is it considered Grp III or IV?

 

I just switched ours over to full synthetic Mobil 1 0w-20 at 75k. It now has 85k on it. Pretty sure my oil pan seeped oil before. Nothing drips on the floor of the garage and oil seepage don't seem to have gotten any worse. I thing the engine runs quieter also.

 

Agreed, full synthetic or not it's a great oil and the price is usually reasonable. Their 0w-40 is one of the best oils around, I would have no problem running it in my TL.

As far as I know the 0w-40 is synthetic as is the EP line and the 0w oils have to have some synthetic content to make grade. I still would not use the 0w-20 AFE oil or any AFE oil in my TL in my climate. I would never be able to get over the low, low HTHS. I've run it when I was in another state where morning temps were in the 15F to 17F range and the drive to work was short, but no way would I run it in the moderate to hot area I currently live in.

I personally like the ester oils. I've consistently seen fewer and even no deposits in the ring land area on teardowns among it's other advantages. Some things make it overkill for a low powered street car but some features are great for the street. I've seen how well Mobil One cleans and if you pull a valve cover of a car run on Mobil One and one run on Redline you're not going to see much of a difference in cleanliness. However the valvetrain cleanliness doesn't translate into better engine performance like having a clean ring land area does. That's one area having lots of detergents can't help, that's mostly the base oil. Either it will or will not cook off.

This reminds me that mine is wet around the drain plug and I need to get a new washer at the next oil change. It's my own fault, I've done about 25 oil changes since it was new and I've never replaced the washer.

 

The ONLY time you will get a leak, switching from conventional to synthetic is if your car has already developed a leak. If it's a small one, it might get a little larger with Synthetic however not much.

Change it if you wish, but at 75k miles and if it's been running fine on regular then why switch?

 

I've been running the M1 0W-40 for a few years now. Not much to say about it other than my engine is quiet and running great with over 140k miles now.

 

I switched to Redline at ~70k. No problems. Engine is quiet. No leaks (from what I can tell). Better sooner than later. Save some wear and get it cleaner, sooner.

 

Its good to see someone thinking outside the box. To show how paranoid I am I have a case of this oil in the garage for either car in case I can't get oil through the mail.

I know at least one other member has run it.

 

I have an 08 Base, had it since 58K miles. I use full synthetic now because that's what was originally in the car wasn't it?

 

Original owner used conventional oil, I bought it with just under 75k miles, and all I have used is synthetic (Penzoil Platinum Plus), no leaks.

 

Mine had dino. I specifically asked when I bought it.

 

yeah i dont believe that was a requirement specified in the manual.

 

I actually experienced this when I switched to synthetic when I had my 2004 Accord. It had approximately 145k miles on it at the time though. Started leaking from the valve covers as soon as I made the switch. On the other hand, I just bought my TL with 119k miles. I put synthetic in for its' first oil change two weeks ago and I haven't noticed any leaks at all. I think the possibility is there but at 73k miles, yours is very unlikely to have problems.

 

I bought my '05 TL at 66k miles, and I bought my '07 type-s at 49k

Both immediately got synthetic blends of oil.

Never had problems. At 73k miles your chances of leaking are incredibly slim.

 

Ive run it.
am running redline 5w-30 currently tho