I will be changing the oil in my R for the third time tomorrow, 9100 miles, and have been using Castrol Syntec 5W-30. I was thinking of switching to Mobil-1 Synthetic since I use Mobil-1 filters anyway. I know oil is oil but could there be any negative effects of changing brands at oil change?

 

Just always use the same width oil and you can't go to regular oil from synthentic.

 

Why?

 

ummm, yes you can. then only thing you shouldnt do is change to synthetic when your car has lots of miles on it. this is because synthetic oils can cause leaks. syntheic oils are more harmful to seals in older engine. changing from synthetic to conventional oil is perfectly fine and will cause no harm.

 

same width oil???? what the hell are you talking about. from this i no that you know nothing or almost nothing at all and no one should listen to what you say cause it is wrong. go learn something about cars before you talk.

 

I think he meant weight. But, that would be wrong also.

Use the weight that the manufacturer recommends. Using a thinner oil in the winter and a thicker oil in the summer is sometimes useful.

I use Mobil 15W-50 in my 1965 Buick Wildcat with no leakage. Gaskets are all factory original.

Grumpy

 

yea, i kinda figured that but, even if he said weight he still would have been wrong since oils dont go by how heavy it is. the correct term is viscosity. when you see the "W" after the first number of a multi viscosity oil it means winter. 5w-30, 10w-30. the "W" means how thick the oil molucules ( <-- ??) is when its below 0 degrees F, well im not sure at what tempature it was rated for, but you get my picture, hopefully. im not really good explaining things.

 

Not necessarily. I changed to synth. on my GSR at 85K and no problems (now 105K, 5 or 6 changes later). I know at least one other person who did the same. Honda engines have very tight clearances and the leaking through gaskets & seals theory might apply more to old American engines but I never heard of any real world cases of that either.

 

I changed to synthetic over 3 years ago at 148,000 miles with no ill effects. I have 187,000 miles on it now. Synthetics are actually easier on the gaskets and seals because they can help reduce operating temps. And they do not cause leaks. They flow better so they will leak better by finding all the little holes that dino oil could not get through.

 

I have been running castrol Syntec Blend in my 140k mile SOHC VTEC as an alternative to full synthetic. This motor has been abused to hell and has seen the redline thousands of times under harsh condition. Motor still runs strong & burns as much oil as a 140k mile motor should. I run 10w30.

 

Chois i-VTEC: Calm down. First off, I am right. Of course you are able to switch to regular oil from synthetic, but it is not a very good idea. After long use of regular oil it builds up on the cylinder walls, then once you change to synthetic that slick built up is removed. Thus it can cause leaks from old gaskets that now have removed regular oil build up. The switching back to regular makes it not safe for your engine. Think about it, please don't try to bad mouth me. I did mean weight, don't ask why I said width.

Also, it is always the safest to stay with the same weight oil. I went over it with my autoshop teacher in depth. He made good points.

 

Please explain how buildup of dino oil on the cylinder walls causes gaskets to leak on a switch to synthetic.

Switching viscosities is important due to temperature changes. If you drive in an Alaska winter then move to a Arizona summer, you most certainly want to change oil viscosities. That's why Mobil 1 makes a 0W-30 and a 15W-50 oil. I admit this is an extreme example.

Grumpy

 

Try reading up on these. I found them helpfull.

http://www.mr2.com/ARTICLE/Mobil1.html
http://www.mr2.com/TEXT/synth_oil.txt
http://www.mr2.com/TEXT/AllAboutSynthOil.txt
http://www.mr2.com/TEXT/OilFacts.txt

 

Good links!!! check this one out too, http://www.vtr.org/maintain/oil-overview.html


[Modified by jweller, 6:31 PM 8/16/2001]

 

All interesting reading. I have been using Mobil 1 since it came out about 1976. I use it in all my cars, my lawn tractor, the generator on my RV, .....

I was just wondering how dino oil adhereing to the cylinder walls cause gaskets to leak when converting to synthetic. Or did I read the post wrong.?

Grumpy - Mobil Oil Corporation employee 1970 - 1996

 

Question for you guys-Why would it be bad to go back to normal oil after using synthetic? Thanks in advance.

 

Good links, thanks. I'll admit, I didn't read all of them b/c of time, but the only thing I would say is too bad Mobil One didn't do an equivalent test with regular dino oil under the same circumstances, with exactly same model cars and engines. So that wasn't exactly a scientific test because there is no control and who knows, under those conditions (inside a closed environment), maybe the regular oil would hold up just fine too. I read part of the other article that compares characteristics btw.

There was a test done by Consumer Reports with regular motor oil on NY city cabs, and I don't have a link, but apparently from that study there was no excessive wear and tear to the engines either.

 

I run organic in summer and synthetic in winter- My rex has 194,000 miles on it and I have not encountered any synthetic induced leaking or burning of oil. My 2 cents.

 

Thats very interesting...

I should have a talk with my auto shop teacher. Well, I don't go to school anymore, but you know what I mean.

 

I believe that regular and synthetic oils have exact protection. Yet, proven synthetic oil stays cleaner, longer. Maybe only in apperence. Unfortunautly. I do however like the use of synthetic, but don't agree with price.

 

I am debating something right now. I have been using mobile 1 synthetic for some time, and replace it about every 2,000 miles. I am thinking about switching to organic oil, and just doing oil changes every 1,000....the cost would probably be the same, or even cheaper changing my oil every 1k with regular oil...and I bet the oil would stay cleaner also? What do you think?

 

This is the information I have accumulated on the subject.

1. Synthetic oil has less friction than dino oil. Since the oil is "made" each molecule is perfect and has no "dangling" electrons to make it "catch" on other "dangling" electrons. Since it has less friction, more HP can go to the rear wheels.

2. Synthetic oil can withstand higher operating temperatures than dino oil. Dino oil starts to drop out "wax" about 280F making the oil much less useful. Synthetic oil has no wax dropout.

3 Synthetic oil costs more, BUT IS NOT more expensive to use. If you change dino oil at 3000 miles, you can go 12,000 miles on synthetic oil with the same protection. (36,000 per year[a lot], six quart capacity, $5/ qt equals $60/year for syn. Same basics, $1/qt. for dino, $60. per year for dino.)

( Say the worst, change Synt at 3000, cost is $240 PER YEAR, less than $1/day, you spend more than that on smokes)

4. I personally, in some of my street cars, changed the synthetic oil every six months (topping off as required). Upon opening the engines, they were basically "perfect" with no sludge WHATSOEVER. It my "better" cars i do change it more frequently because I want to. Fuel dilution of the oil being a concern.

5. OIL IS SUPPOSED TO BE DIRTY. Its job is to pick up dirt and hold it in suspension. That's why you change oil when its hot, so the suspended dirt is removed with the oil. In my race car the oil is clean because it goes about only TWENTY FIVE HOURS between rebuilds (and it is changed every three hours), rather than thousands of hours for a street car.

6. Mobil has conducted tests where the car has been driven over 1,000,000 miles and with proper oil changes, the wear was minimal.

7. They have also kept the same oil in a car for a full year and the oil still tested and complied with specifications for new oil. Mobil will NOT recommed this because it violates OEM requirements and they want to sell more oil.

SUMMARY

less friction, more available HP, less wear, not more expensive, better protection.

Check out what the "big boys" use, not what is says on the car, not what is says on the can, but what is really in the can. The one in the back of their pits, not the one up front for the sponsor.

Flame away, I'm headed out to the track any won't be back till Monday.

Grumpy