1985 Toyota MR2 oil selection and UOA question

Messages
136
Location
Whitby Ontario Canada
This car was brought to me by a friend of a friend. It is owned by the original owner, IMMACULATE condition, never seen precipitation, original everything including tires and brakes!

Last time the oil was changed was 2015 which I kid you not was 1000kms ago. It was done by the local Toyota dealership.

He has expressed the desire to continue with conventional oil (5w-30) although he admits the length of time between oil changes was neglect on his part and vows not to do it again. We both (out of curiosity) decided to do a UOA just to see how it actually held up and if there's any notable wear to the motor. Problem is I don't know what the source oil is to be able to compare to the UAO. When he contacted the dealer with the part number from 2015, they responded that it is a bulk oil from esso that they "customize with their own additive formulation."

My two questions are: 1. Would it be useless to do a UOA if the VOA is unknown? And 2. What exactly do I tell him to use as a good conventional oil and OCI given the minimal road time it sees?

Thanks!
 
Messages
175
Location
Brazil
I don't know what Toyota specs for that car, but i have seen people using 10W40 and 5W40.

If he wants to stay with conventional, maybe a 10W30 would be a good choice (temps permitted).

I would do a UOA after he uses the car a bit and after his first known OCI.
 
Messages
172
Location
Arizona
A UOA will give you important info about the engine even if you don't know the oil. My coworker has an '86 and he found out it was specified for 10w-40. I honestly don't know if that's true and just rolled with it considering the vehicle came from the 80's. I told him to get Castrol and so far he likes it. His motor has well over 200k also. Car is pretty clean in and out, too!
 
Messages
4,497
Location
Massachusetts
FWIW, I change my Willys Jeep every 3 years. My trail Jeep is every 2.

If it's taken care of as well as you state, I think it will be fine. the UOA will likely indicate "Lot's of Active Additive Remaining" as Blackstone likes to put it. IMO, knowing the brand of oil sample is irrelevant if the numbers are good.
 

STIcandy

Thread starter
Messages
136
Location
Whitby Ontario Canada
A UOA will give you important info about the engine even if you don't know the oil. My coworker has an '86 and he found out it was specified for 10w-40. I honestly don't know if that's true and just rolled with it considering the vehicle came from the 80's. I told him to get Castrol and so far he likes it. His motor has well over 200k also. Car is pretty clean in and out, too!
Yes, I have the original repair manual, and you are correct, it does spec 5w-30 for winter 10w-30 even 10w-40 within the operational temps of summer. I'll have to take a picture later and post. Having said that were talking 35 years ago and oil technology/quality has improved vastly since then. Last oil change was 5w-30, and being that he has decided to stay conventional I chose QS Advanced Durability 5w-30 as it seems to be a pretty robust oil.

My biggest concern with a vehicle of this age, is the additives we use now as apposed to what was used then. With this being an OHC engine with followers, should I be considering a higher zinc oil or zinc additive? I know this is primarily a problem with older/modified hot rods but (full disclosure) I was 4 when this car was new, so I'm not sure what is required.

As motor oil has improved for use in modern engines, it hasn't necessarily been benefitial for some of the relics from the past....
 
Messages
7,042
Location
Wet side WA
Yes, I have the original repair manual, and you are correct, it does spec 5w-30 for winter 10w-30 even 10w-40 within the operational temps of summer. I'll have to take a picture later and post. Having said that were talking 35 years ago and oil technology/quality has improved vastly since then. Last oil change was 5w-30, and being that he has decided to stay conventional I chose QS Advanced Durability 5w-30 as it seems to be a pretty robust oil.

My biggest concern with a vehicle of this age, is the additives we use now as apposed to what was used then. With this being an OHC engine with followers, should I be considering a higher zinc oil or zinc additive? I know this is primarily a problem with older/modified hot rods but (full disclosure) I was 4 when this car was new, so I'm not sure what is required.

As motor oil has improved for use in modern engines, it hasn't necessarily been benefitial for some of the relics from the past....
LOL and frankly its very questionable how beneficial some of those things are in any car new or old.
 
Messages
172
Location
Arizona
Yes, I have the original repair manual, and you are correct, it does spec 5w-30 for winter 10w-30 even 10w-40 within the operational temps of summer. I'll have to take a picture later and post. Having said that were talking 35 years ago and oil technology/quality has improved vastly since then. Last oil change was 5w-30, and being that he has decided to stay conventional I chose QS Advanced Durability 5w-30 as it seems to be a pretty robust oil.

My biggest concern with a vehicle of this age, is the additives we use now as apposed to what was used then. With this being an OHC engine with followers, should I be considering a higher zinc oil or zinc additive? I know this is primarily a problem with older/modified hot rods but (full disclosure) I was 4 when this car was new, so I'm not sure what is required.

As motor oil has improved for use in modern engines, it hasn't necessarily been benefitial for some of the relics from the past....
There are modern DOHC engines that use flat cam followers, like the Kia/Hyundai 2.4. It's those old pushrod engines with flat tappets that need ZDDP. Those things have a very aggressive cam profile and only 1 cam doing all the work. The 4A-GE is a high revving engine, but if you're just driving it around taking it easy and not abusing it, it shouldn't need additives. I'd be more worried about it burning oil, so conventional or cheap synthetic oil changes for 3000 miles or 6 months would be my choice to keep the engine clean.
 

STIcandy

Thread starter
Messages
136
Location
Whitby Ontario Canada
There are modern DOHC engines that use flat cam followers, like the Kia/Hyundai 2.4. It's those old pushrod engines with flat tappets that need ZDDP. Those things have a very aggressive cam profile and only 1 cam doing all the work. The 4A-GE is a high revving engine, but if you're just driving it around taking it easy and not abusing it, it shouldn't need additives. I'd be more worried about it burning oil, so conventional or cheap synthetic oil changes for 3000 miles or 6 months would be my choice to keep the engine clean.
This car litterally gets driven 500kms a year maybe. I'll just tell him to change the oil once a year. Maybe the filter every other.

Yeah just after I posted I was reading about the flat tappets. This isn't an issue here. I will be going with 10w-30 though at that's what the manual specs it for in his operating conditions. Any preferences between QSAD or Penzoil?
 
Messages
7,042
Location
Wet side WA
This car litterally gets driven 500kms a year maybe. I'll just tell him to change the oil once a year. Maybe the filter every other.

Yeah just after I posted I was reading about the flat tappets. This isn't an issue here. I will be going with 10w-30 though at that's what the manual specs it for in his operating conditions. Any preferences between QSAD or Penzoil?

The one on sale with a rebate!
 
Messages
3,751
Location
Nashville, TN via Memphis
Wow, what a cool car!

Isnt this the one with very angular, wedge-like styling, and the “slat vents” in the engine cover?

We need you to do a photo shoot of this car and post the pics!

LOVE ‘80s Japanese cars!
 

STIcandy

Thread starter
Messages
136
Location
Whitby Ontario Canada
That would be a really cool car to have. Why not run a full synthetic?? Just curious.
no idea why this post is all underlined. Guess I must have hit something.
Lol. The answer I got from my buddy was that it has been run on conventional its entire life so he didn't want to chande it now. I wanted to use Motul in it.
 

STIcandy

Thread starter
Messages
136
Location
Whitby Ontario Canada
Wow, what a cool car!

Isnt this the one with very angular, wedge-like styling, and the “slat vents” in the engine cover?

We need you to do a photo shoot of this car and post the pics!

LOVE ‘80s Japanese cars!

Here's a few I snapped when he brought the car over....
 

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Messages
3,751
Location
Nashville, TN via Memphis
Awesome, man!

Would love to see some more pics, if you get the chance.

It would be so cool to get to take that MR2 out for a drive on some tight, twisty roads! The suspension and brakes would probably be found to be lacking, but that’s nothing the aftermarket can’t cure, and that car would be worth spending some money on upgrades!

Is that your blue STi in the background?
 
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