Is it ok to mix and match oils in a car once?

[ARCHIVED THREAD] - Is it ok to mix and match oils in a car once?

Posted: 8/11/2005 8:06:16 AM EDT

Hello I just purchased a used vehicle and I have no idea what brand oil is in the car. It's still a smooth honey color so its still good to go. The car needs about 1 to 2 quarts more oil in it and I happen to have some Castrol GTX laying around in the correct weight.

So do you think it would be wise to add 2 quarts of Castrol to the mystery oil already in the vehicle or would it be better for me to go get an oil change and know whats inside my engine?

Thanks! Just trying to save some money.

Posted: 8/11/2005 8:09:44 AM EDT

[#1]

When I buy a used car, I flush the ATF, change filter and refil with good ATF. I also change the oil right away too. Better safe than sorry. This will save you lots of money later.

PS what kind of vehicle?

Posted: 8/11/2005 8:11:10 AM EDT

[#2]

2005 Chevy Malibu with 29k on it.

Posted: 8/11/2005 8:11:40 AM EDT

[#3]

No problem, its better than to be without oil.

Posted: 8/11/2005 8:13:18 AM EDT

[#4]

Quoted:
2005 Chevy Malibu with 29k on it.

I would then just top off the oil and change the filter if it looks good.

I would still do the ATF though. its about that time anyway. 29k? may as well do it now.

Posted: 8/11/2005 8:13:38 AM EDT

[#5]

Mixing oils are alright.
Never mix coolants!!!

Posted: 8/11/2005 8:14:31 AM EDT

[#6]

Change it and know what oil is in the motor.

Posted: 8/11/2005 8:14:56 AM EDT

[#7]

Quoted:
Mixing oils are alright.
Never mix coolants!!!

+1

Posted: 8/11/2005 8:21:07 AM EDT

[#8]

What is wrong with mixing coolants?

I topped off my Coolant reservoir last month.

Posted: 8/11/2005 8:25:14 AM EDT

[#9]

Quoted:
What is wrong with mixing coolants?

I topped off my Coolant reservoir last month.

Depends on the make.

Posted: 8/11/2005 8:44:37 AM EDT

[#10]

Quoted:
Quoted:
What is wrong with mixing coolants?

I topped off my Coolant reservoir last month.

Depends on the make.

I added a mixture of Peak and water. I don't know what was in there before.

Posted: 8/11/2005 8:48:51 AM EDT

[#11]

Quoted:
Quoted:
2005 Chevy Malibu with 29k on it.

I would then just top off the oil and change the filter if it looks good.

I would still do the ATF though. its about that time anyway. 29k? may as well do it now.

Huh?

Did you mean the air filter?

Posted: 8/11/2005 8:51:13 AM EDT

[#12]

You can mix and match just about any kind of auto oil.
I never change the ATF, just top off if neccessary. Back in the day that was bad news. Now they change ALL of the oil (pump, ect.) from what I hear. I'm still not doing it.

Posted: 8/11/2005 8:52:53 AM EDT

[#13]

Quoted:
You can mix and match just about any kind of auto oil.
I never change the ATF, just top off if neccessary. Back in the day that was bad news. Now they change ALL of the oil (pump, ect.) from what I hear. I'm still not doing it.

Remind me to never ever buy a used car from you.

I change my ATF oil and filter every 25K.

Posted: 8/11/2005 9:00:07 AM EDT

[#14]

mixing coolants?

.
.

When you mix coolants like GM dex cool/FORD specialty orange coolant with Generic green antifreeze they'll cake up(brown crap like mud) over time and block cool the coolant flow causeing the vehicle to over heat.

Get a power flush done if your not shure of what's in it.

Posted: 8/11/2005 11:21:19 AM EDT

[#15]

I believe you should NOT mix oils if ione is SYNTHETIC and one is REGULAR.

I am not a mechanic nor did I stay at Holiday Inn last night.

Posted: 8/11/2005 11:23:23 AM EDT

[#16]

Quoted:
I believe you should NOT mix oils if ione is SYNTHETIC and one is REGULAR.

I am not a mechanic nor did I stay at Holiday Inn last night.

Pretty sure you don't want to mix different types of oils, such as synthetic and standard oil.

Different brands though, can be mixed. If you need to add some, just try to keep it the same viscosity.

Posted: 8/11/2005 11:36:06 AM EDT

[#17]

Don't be cheap. Change the oil. The extra 4 dollars you would save aren't worth the risk.

Posted: 8/11/2005 11:37:54 AM EDT

[#18]

I think a better question would be:

If the oil appears to be new (ie; the people you just bought the car from just changed the oil before you bought the car), why is it 2 quarts low?

As a general rule, you can mix brand names of oil, but it's not a good idea to mix different viscosities of oil. In other words, don't put 10W40 in if you had 5W30 in it already.

Posted: 8/11/2005 11:39:06 AM EDT

[#19]

Quoted:
Quoted:
I believe you should NOT mix oils if ione is SYNTHETIC and one is REGULAR.

I am not a mechanic nor did I stay at Holiday Inn last night.

Pretty sure you don't want to mix different types of oils, such as synthetic and standard oil.

Different brands though, can be mixed. If you need to add some, just try to keep it the same viscosity.

Never heard of sythetic blends?

Posted: 8/11/2005 11:41:32 AM EDT

[#20]

Quoted:
I believe you should NOT mix oils if ione is SYNTHETIC and one is REGULAR.

I am not a mechanic nor did I stay at Holiday Inn last night.

You can mix synthetic and regular all day long.

Posted: 8/11/2005 11:42:15 AM EDT

[#21]

Quoted:
Quoted:
Quoted:
2005 Chevy Malibu with 29k on it.

I would then just top off the oil and change the filter if it looks good.

I would still do the ATF though. its about that time anyway. 29k? may as well do it now.

Huh?

Did you mean the air filter?

oil filter. unless they have a decent one in there. Most have crappy filters. But since you mentioned it, do the air filter too.

Posted: 8/11/2005 11:46:00 AM EDT

[#22]

Quoted:
Quoted:
I believe you should NOT mix oils if ione is SYNTHETIC and one is REGULAR.

I am not a mechanic nor did I stay at Holiday Inn last night.

You can mix synthetic and regular all day long.

My car uses ONLY synthetic. My understanding is you do not want to put regular in it. Of course, an engineering and 2 years of German are required to change the oil in my vehicle...

Posted: 8/11/2005 11:48:41 AM EDT

[#23]

Quoted:
Quoted:
Quoted:
I believe you should NOT mix oils if ione is SYNTHETIC and one is REGULAR.

I am not a mechanic nor did I stay at Holiday Inn last night.

You can mix synthetic and regular all day long.

My car uses ONLY synthetic. My understanding is you do not want to put regular in it. Of course, an engineering and 2 years of German are required to change the oil in my vehicle...

My understanding is that you can't use regular oil for a long time then switch to synthetic due to seals and degradation.

Posted: 8/11/2005 11:50:19 AM EDT

[#24]

Quoted:
mixing coolants?
.
.

When you mix coolants like GM dex cool/FORD specialty orange coolant with Generic green antifreeze they'll cake up(brown crap like mud) over time and block cool the coolant flow causeing the vehicle to over heat.

Get a power flush done if your not shure of what's in it.

Oh, terrific.

Posted: 8/11/2005 11:51:20 AM EDT

[#25]

Quoted:
Quoted:
Quoted:
Quoted:
I believe you should NOT mix oils if ione is SYNTHETIC and one is REGULAR.

I am not a mechanic nor did I stay at Holiday Inn last night.

You can mix synthetic and regular all day long.

My car uses ONLY synthetic. My understanding is you do not want to put regular in it. Of course, an engineering and 2 years of German are required to change the oil in my vehicle...

My understanding is that you can't use regular oil for a long time then switch to synthetic due to seals and degradation.

Thats untrue. You can use synth in any age engine anytime. I switched in my van at 90k switched in my pathfnder at 65k, we did my brothers 145k hyndai. Not a leak problem anywhere.

Posted: 8/11/2005 12:11:19 PM EDT

[#26]

If you can afford the car, you can afford to take good care of it...

I work on gearing and lubrication applications for a living and here is my .02$

Don't mix lubricants...(some manufacturers use additives that may not mix well)

Change the oil and filter.

Be sure to install the lube recommended by the manufacturer's owner's manual.

(Take climate and season into consideration)

ATF doesn't last forever. Have it serviced by a qualified mechanic and you will have a long and happy relationship with your new baby.

Posted: 8/11/2005 2:39:51 PM EDT

[#27]

Quoted:
Quoted:
Quoted:
Quoted:
2005 Chevy Malibu with 29k on it.

I would then just top off the oil and change the filter if it looks good.

I would still do the ATF though. its about that time anyway. 29k? may as well do it now.

Huh?

Did you mean the air filter?

oil filter. unless they have a decent one in there. Most have crappy filters. But since you mentioned it, do the air filter too.

Okay. You may as well change the oil at that point.

Posted: 8/11/2005 2:47:06 PM EDT

[#28]

Lots of bad info in this thread.

bobistheoilguy.com

Posted: 8/11/2005 2:50:07 PM EDT

[#29]

ATF = Automatic Transmission Fluid?
I'm not good with mechnical stuff

Posted: 8/11/2005 2:57:58 PM EDT

[#30]

won't hurt anything.

Posted: 8/11/2005 7:52:43 PM EDT

[#31]

I wouldn't worry to much about mixing brands. If you're a little low, I'd just change it and start using your favorite oil from now on. I'd be more concerned about mixing types, 10W30, W20 or whatever.

Just change it.

Posted: 8/11/2005 9:42:58 PM EDT

[#32]

If you buy a used car, might as well just change all the fluids right after your purchase. Spending $100-$150 isn't a whole lot, especially for the piece of mind you get.

Change your filters too. Make sure your tires are inflated properly, and make sure the grease fittings are topped off.

Have a trusted and qualified mechanic do a good visual inspection as well.