Using a single weight SAE50 in a modern engine?

[ddombrowski]

So I'm wondering how serious the effects would be if I were to run a straight SAE 50 weight oil in a modern engine? I realize that the viscosity will be higher on cold start, and normally I wouldn't do it, but I have some interesting circumstances.

My sister is currently driving a 2000 Mitsibishi Eclipse Spyder with 156k on it. The car is a total jalopy - leather ripped, dashboard cracked, paint peeling, bumper cracked and dragging, radio doesn't work, and the thing [censored] oil to no end from the front crank seal. Its worth very little, hence thats the car she has in college.

Like I said, the car [censored] oil, so she has to add oil alot. Autozone has a sale going on right now for 50% off Valvoline SAE50 (1.99 down to 1.00/qt). I'm liking the idea for several reasons:

1 - $1.00/qt is cheap for good oil
2 - 50wt at room temp (and while hot) will leak less through the crank seal. Yes, I know, it should be fixed. It won't be, trust me.
3 - We live in Florida. Its hot, especially now over the summer. Temps rarely go below 70, even at night.
4 - I think the danger of running the car out of oil because she didn't check it and it leaked out is far higher than the additional wear from cold starts.

Is my logic sound, or am I pushing it too far?

 

[ddombrowski]

BTW, car has the 3.0L V6 in it.

 

[brandini]

20W-50 would be better since 20W while cold is still thicker than a 50W while hot. You want to PROMOTE oil flow at start not hinder it or you'll shorten the life of the car.

 

[addyguy]

Go for it.

In a Florida summer, it's not going to hurt anything.

I think your reasoning is perfectly sound.

 

[suspiciousmind]

In Australia, that's pretty standard juice I think....maybe we'll hear from them when they wake up again.

 

[d00df00d]

Originally Posted By: ddombrowski
2 - 50wt at room temp (and while hot) will leak less through the crank seal. Yes, I know, it should be fixed. It won't be, trust me.

If it gets bad enough, she might get cited for dumping fluids on public roads. Seriously. All it takes are a long traffic light and one bored cop.

Either way, if it's as bad as you say, I doubt that even that thick of an oil will make a significant difference.


Originally Posted By: ddombrowski
3 - We live in Florida. Its hot, especially now over the summer. Temps rarely go below 70, even at night.
4 - I think the danger of running the car out of oil because she didn't check it and it leaked out is far higher than the additional wear from cold starts.

Good points. Ditto the one about the price. It might be worth a shot.


But seriously, friends don't let friends (let alone siblings) drive the Exxon Valdez on public roads. A front main seal shouldn't be too bad a job. Besides, it sounds like most of the neglect you described is cosmetic. The powertrain might have a decent amount of life left in it.

 

[Bluestream]

Recuring topic; check the search...

 

[JT1]

Originally Posted By: Bluestream
Recuring topic; check the search...


In case you haven't noticed, 95% of the threads on here are recurring topics.

Someone wants to be mod for a day!

 

[d00df00d]

Ease up. It's valid advice.

 

[ddombrowski]

I searched google and I searched for "SAE 50" and didn't come up with anything, so I guess I didn't search hard enough. My bad. I didn't think it would be that discussed since usually there would be no benefit (like 50% off) to running straight 50wt to say 20w50.

Anyway, I appreciate the responses. The car doesn't leak THAT much oil, but if you had just pressure cleaned your driveway, you'd get real upset really quick.

I'd say it probably leaks about a CD sized splotch each night its parked. It needs about 1 qt/500-1000 miles. Sorry if I was overdramatic.

Well, I'm off to try to score some VR1 after work today!

 

[FL_Rob]

Find some stop leak (EX.Bars Leak,Main Seals)as a short term fix ,look in the additives section of this site. QT/per 1k ,thats not too terrible.The seal conditioners is what you're after,not necessarily just a thicker oil.

 

[OilBlazer93]

Originally Posted By: brandini
20W-50 would be better since 20W while cold is still thicker than a 50W while hot. You want to PROMOTE oil flow at start not hinder it or you'll shorten the life of the car.


+1,000,000!

You have an Oil Leak as well out of the Chrysler/Mitsu V-6? .. Well, if its Severe it -may- just be something to be mechanically repaired, but try Lucas Stop-Leak. it depends 100% on where the Stop-Leak IS.

But 20W-50 is a good choice.

I like your thinking of Thick Oil.

 

[ddombrowski]

Originally Posted By: brandini
20W-50 would be better since 20W while cold is still thicker than a 50W while hot. You want to PROMOTE oil flow at start not hinder it or you'll shorten the life of the car.


I'm not sure I understand you. 20W cold is thicker than 50W hot - yes, but 50W cold should be thicker than 20W cold, shouldnt it? Basically, the straight 50W oil will always be thicker (or as thick) as a 20W50.

I understand that you want to promote oil flow on cold startup and that going to a thicker oil (cold) goes against that. My point was that I would rather sacrificate cold start wear for cold-sitting leak rate and oil supply cost, and that I thought it was a good trade off to prevent the engine from running dry.

Also, being that the oil is so cheap, if she can get a bunch of it for not a lot of money, she'll be more likely to keep it topped off if she has the oil on hand rather than skip it because she only bought a quart or two at regular price.

 

[d00df00d]

Guys, please try not to use W to describe an oil's "weight", or viscosity @ 100º C. A lot of people do it (including me until several months ago) but it's misleading.

The W in 20w-50 stands for "winter," not "weight." It is a measure of pumpability at low temps. The 50 is kinematic viscosity at high temps. Two different measurements that are not comparable.

A 20w-50 will most likely be more pumpable when cold than a straight SAE 50. However, when both oils are around 100º C, they will both have similar kinematic viscosities, and kinematic viscosity is probably the measurement that will have the closest correlation with how quickly the oil seeps out of a seal. That's why a 20w-50 might be a better solution than an SAE 50 for this case: you get the hot viscosity of an SAE 50 without as much of a disadvantage in cold starting.

Of course, both oils are vastly too thick for that engine. It's just that the 20w-50 will be less so on a cold start.

 

[ddombrowski]

thanks d00d! I learned more than I expected to. Will have to remember that about the w, I didn't know, whoops.

I guess the 20w50 would be the better option then as it gives the best of both worlds, but the 20w50 is more than 2x the cost of the straight 50w. Being that we're in Florida in the summer, I don't think its that big of a deal, and the car will likely be sold at the end of summer or early winter. Its my fathers car, and I don't like to get involved in repairs of it as I often never see my money back, but if I can recommend an oil to my sister to pick up and improve her situation a bit, I'll do it.

 

[Bluestream]

You can use the 50W without problems. Keep in mind that the $5-6 you save on the oil will long be used up in the higher fuel consumption that a 50W will bring. Also, a bit more sluggish feel to drive, but if the goal is to reduce consumption, it will help. As suggested a seal swell product may be a better choice.

 

[OilBlazer93]

Originally Posted By: ddombrowski
thanks d00d! I learned more than I expected to. Will have to remember that about the w, I didn't know, whoops.

I guess the 20w50 would be the better option then as it gives the best of both worlds, but the 20w50 is more than 2x the cost of the straight 50w. Being that we're in Florida in the summer, I don't think its that big of a deal, and the car will likely be sold at the end of summer or early winter. Its my fathers car, and I don't like to get involved in repairs of it as I often never see my money back, but if I can recommend an oil to my sister to pick up and improve her situation a bit, I'll do it.


I will help you here, as ive had some vehicles that were Amazing, in that they still ran..

The Oil capacity of your car is listed as "4 Quarts." Small for a V-6.. But do this:

1) Add -1- of those Quarts as Lucas Stop-Leak. IF YOU WANT TO HELP "SEAL" THE LEAK.. Sounds un-sealable based on what kind of leak you said it was, bu tthis is about your best show.

2) Add 3 Quarts MaxLife 20W-50. NOT THE CHEAPEST STUFF YOU CAN BUY!

You could spend:

a. $10 for the Lucas Stop Leak and $5 a Quart for the Valvoline MaxLife, which is a good -Sealer HELPER- (Little small leaks youd never see or know about, thanks to the Oil.)

b. $500 plus $300 for New Engine, Cost and Install

c. $300-$500 for New Car.

Im Just Saying.

 

[aquariuscsm]

I have a friend who used nothing but GTX 20W50 in his 200,000+ mile Stealth with the SOHC 3.0 V6 (same engine in her Eclipse) and it ran flawlessly,and he literally pounded the life out of that car! 20W50 will work perfectly in her car,the VR1 being a great oil.

Go for the 20W50 VR1 (or actually any 20W50).

 

[ddombrowski]

Originally Posted By: OilBlazer93


I will help you here, as ive had some vehicles that were Amazing, in that they still ran..

The Oil capacity of your car is listed as "4 Quarts." Small for a V-6.. But do this:

1) Add -1- of those Quarts as Lucas Stop-Leak. IF YOU WANT TO HELP "SEAL" THE LEAK.. Sounds un-sealable based on what kind of leak you said it was, bu tthis is about your best show.

2) Add 3 Quarts MaxLife 20W-50. NOT THE CHEAPEST STUFF YOU CAN BUY!

You could spend:

a. $10 for the Lucas Stop Leak and $5 a Quart for the Valvoline MaxLife, which is a good -Sealer HELPER- (Little small leaks youd never see or know about, thanks to the Oil.)

b. $500 plus $300 for New Engine, Cost and Install

c. $300-$500 for New Car.

Im Just Saying.


Thanks. I will take a look at the Lucas stop leak. Right now, the car is up at school and I probably won't see it until the end of summer. Once that happens, the car may be given to me to patch up to sell it, which will likely involve slowing the leak, patching up the bumper, fixing the radio and calling it a day.

Its not that I think the car is unviable, but we have too many right now and that is the car we need the least. Although, it is a vert, and despite the fact that the eclipse spyder is a total chick car, I love driving with the top down.

BTW, went to autozone last night to try to score on the oil deal - for some reason, the SAE50 wasn't showing up at the correst price (.99) but the 20W50 was (2.25) so I bought 8 quarts of that and will probably try to go back for more later.

Thanks guys!

 

[mechtech2]

There are a handful of street vehicles that may be able to properly use a straight 50 oil.
But very very few, and very very few circumstances of driving that would allow this.