I use normal oil right now and I change my oil every 2000 miles, I am planning on changing to Mobile 1 Synthetic and I was wondering how many miles I should run it before I change the oil with the synthetic, thanks for your help.

 

I'm sure everybody has their own opinions on this issue, so I'll give you my version.

No matter which oil I use (Mobil 1 in my Firebird and regular 10W/30 in my Suburban), I change the oil every 3000 miles. Period. Sometimes I slip closer to 4-5K , but usually it is every 3000 miles.

You could drive even more miles with either oil, but I just want to make sure it stays as fresh as possible.

Later!

TS

 

Like 95GRNZ said.. opinions vary... I believe it depends on your driving habits.... If you are mainly city driving, then more contaminates and fuel get into the oil from stop and go driving.. If your on the highway more then its less....

I run syn and change mine 5-6 thousands miles and had no probs, but its mainly highway..... Dino oil was around 2500-3500 miles..

 

My drain plug got stuck in my car and i ran mobil 1 10w30 for 8k miles and the stuff didnt even look dirty!! But on a regular basis i would always change the oil at 3k miles, better safe than sorry! You know all those muscle cars runnin around with 100k+ on the ticker??? that is because they always had their fluids changed on schedule, moral of the lesson: take care of your car and you shall be rewarded!!! <---corny but true

 

The argument about the tradeoff of many miles (more than 5000) between synthetic oil changes and low miles with standard oil(3000) usually involves claims that a particular oil will "last longer". If you pull the dipstick from most engines with even 10,000 miles on the oil, the oil will still feel slippery. It "can" still lubricate. The reason for the quote marks is, the oil is usually not the problem; it is other things in the oil.

While running, an internal combustion engine always has some leakage past the piston rings. That is; unburned fuel as well as combustion products get past the rings into the oil. Unburned fuel can wash oil from the cylinder walls causing wear. Wear produces metal particles in the oil. Your oil filter will trap particles over a certain size, but smaller particles will pass through the filter and circulate through the engine, causing wear on bearings, rings and cylinder walls. The combustion products include many compounds, including acids that will both combine with and break down engine oil. Synthetic oil will resist breakdown better than regular oil but carry particles just as well. Additives to any oil are also subject to chemical change due to combustion products that can reduce their effectiveness and may even make them harmful. An oil filter will not remove liquid chemicals that result from combustion.

I run Mobil 1 and change it every 4000 miles. I'm not worried about the oil loosing it's lubricating properties beyond that, I'm worried about all the contaminates that find there way into the oil pan. Oil filters only catch particulates, not liquid chemicals. Be safe and change your oil and filter often.

 

Changed my oil today.. did dyno runs before and after..

I went about 4-5K miles on my Mobil 1..

I will try to go about 10K on this one.. Just for grins..

What good is more expensive oil if it is not reducing the number or oil changes you have to do?

(info on todays dyno runs are in the review section in sig)

 

Here's one for ya...

We started using Mobil 1 in my girlfriends '99 Solara (yeah, I know!) at 7500 miles. I had good luck with it in my '94 Z28, plus she was the type to forget, and let it go for too long.

Well, it turns out Toyota had a big problem with their V6 that year. They reduced the size of the coolant passages in the heads, in order to run the combustion chambers hotter and reduce emissions. This change made the oil circulating in the heads burn, and sludge up. Engines running regular non-synthetic oil would sludge up to the point that oil would no longer circulate back down to the pan - and the engine would be toast! Many owners lost their engines just after the warranty expired.

Interestingly, engines running synthetic did not have this problem, as synthetic has a much higher breakdown temp. She has over 100k now, running Mobil 1, with no sludge problem.

So, in this situation, running synthetic really paid off.

 

Well guys, thanks for all the input, I plan on using Mobile 1 5w30 and I think I will run it 4000 miles in between every oil change. With the dino oil, I used to change my oil every 2000 miles, just to keep the car in good shape.

 

I'll throw in my $.o2 to this. On my Formula I change it every three months, but that is about only 1500 to 2000 miles and I use mobil 1. The reason is because the additives in oil break down over time. I could probably go to 6 months but why chance it. Ever wonder why they say change it at 3000 miles or 3 months, which ever occours first. Because all the additives begin to break down and not be useful. Just for comparison sake, I have an old beater pickup that is 16 years old and only has 32,000 miles on it. I still change its oil every 3 months even though I only put 5000 miles a year on it. But that gets regular oil. When you change the oil is up to each person, but this is just my feelings on it. My truck has ran great for 16 years and I expect the formula will do the same. Oh, i don't put to many miles on my car because I have a company vehichle to drive around to and from work. Saves many miles on the car. But when I do drive it, boy do I have a good time. Nothing better then a v-8 roaring in the cool night air.

 

Here's my schedule:

change synthetic oil every 6,000 miles
change oil filter every 3,000 miles

I've read other posts that say changing synthetics more often is a waste of $$. I've done this w/o any problems. But now you guys have me wondering if more frequent changes are needed

 

well, one way to find out is to take an oil sample and have oil analysis done at about 2K, 4K and 6K miles.. if the results are good, then you will know you are safe still.. I personally am going to be pushing the 10K.. mainly cause even though my oil comes out black I know that its still doing its job.. maybe not as good as day one.. but still good enough that its not building crap up..

 

I have always gone 3k on mobil 1. Last time I went out to about 4k and the oil came out significantly darker. I think I will stick with 3k intervals.

 

...I once drove to LA, California from Chicago, IL, to stay with my dad for like a 3 week vacation drove all over southern cali, and then came back home and then changed my oil and mobile looked like it was still pretty viscous. I mean Mobile 1 has to be the best...

 

Most of that 3000 mile oil change stuff came from the oil change companies.

Look at your manufacturer recommendation.

I use Penzoil 5W30 in my 1989 Blazer. I change it every 5000 miles. There is 214,000 miles on it now. Other than valve cover gaskets, I've never been in the motor. Oh yeah, it's got 4.56:1 gears spinning 38-inch tires, so it's not like I baby it. It also tows my car trailer.

My GN has had Mobil 1 5W30 since new. At 90,000 I went into the motor for performance mods and couldn't see or measure any wear. It gets changed every 5000 miles, but only because it is constantly being abused.

The Camaro will be changed every 5000, but only because it's easier to remember (and it's getting abused, too!)

I think the recommended intervals are 7500 for regular oil and 15000 for synthetic.

 

My oil change indicator usually comes on at about 5,000 miles on my 02 SS as well as my 01 Silverado. For the past few years now, I have always used 5,000 mile intervals (dino oil) on all my vehicles. I've never had a problem. Consumer Reports did a test with NYC taxi cabs where they did 3,000 mile changes in some and 5,000 mile changes in others. I think it ran for over 50,000 miles and there was no noticable difference in the motors when disassembled. The 3,000 mile thing was started decades ago when oil technology wasn't as advanced as it is today. Synthetics brag that they can be used for 20,000 to 25,000 miles with regular filter changes. I'll go with 10,000 for now. I just started using synthetics last year when I got my SS. The Amsoil dealer says for me to leave it in longer. But he doesn't complain too much when I by another case from him.

Summary - If GM tells me to change the dino oil every 5,000 miles, synth ought to be able to safely go 10,000 without a problem. Just change the filter at least every 5,000 miles. I currently slap a new filter on at 4,000 and 7,500.