Getting a co-workers 2 dr 97' 4X4 Tahoe in Feb...Oil Questions..

[dirtbikerdude2005]

I'm getting a very well cared for Tahoe in late February. The owner works at the dealership and will get a mechanic to replace the rear main seal and do a tranny service..all of this for $500 bucks outta my pocket. Then I will take ownership and immediately change the oil. It has 120K on its original motor. I'm considering using Amsoil 0W-20 XL Synthetic...but is it a bad idea to use synthetic on a motor with 120K? Also I'm planning on changing both diff lubes, antifreeze, air cleaner, etc. Thanks in advance!!!

 

[Evil 'Bird]

I'm getting a very well cared for Tahoe in late February. The owner works at the dealership and will get a mechanic to replace the rear main seal and do a tranny service..all of this for $500 bucks outta my pocket. Then I will take ownership and immediately change the oil. It has 120K on its original motor. I'm considering using Amsoil 0W-20 XL Synthetic...but is it a bad idea to use synthetic on a motor with 120K? Also I'm planning on changing both diff lubes, antifreeze, air cleaner, etc. Thanks in advance!!!

if they are doin the rear main, why not tell them to put the synthetic in?

i dont think u should have a problem with using synthetic on 120k....i did it to mine and countless other cars/trucks... old motors

i use Royal Purple 5w-30 best oil ever,...i would use that or Mobil 1 5w-30

Amsoil is good too. But why do u want to run 0w-20?

where are u located and what temperture u gonna be runnin in?

 

[haks310]

The only reason people discourage using synthetic in high mileage engines is because of the risk of magnifying or creating leaks. The molecules in synthetic are smaller so they seep much easier.

I switched to Mobil 5W-30 at 75K miles. I am at 88K miles now and have had no major leaks or oil spots covering the driveway to worry about.

Why 0W-20?

 

["350Vortec"]

I switched from conventional to synthetic with my truck having 168,000 on it. No problems ever .

 

[dirtbikerdude2005]

I want to use 0W-20 because it's thinner/lighter. This would allow the motor to crank & run easier. Also i would think the thinner oil would get in the nooks crannies faster on startup, plus better gas mileage the easier the motor turns. I live in North Florida.

 

[James909]

I personally would stay away from the 20 weight oils, especially on a motor that doesn't call for it. It's too thin IMO to provide adequate protection. And I doubt that you would even notice a difference in mpg. We're talking tenths of a mpg difference. Some newer cars call for it because with the CAFE (Corporate Average Fuel Economy) requirements saving these miniscule mpgs multiplied over thousands of vehicles can save them significant amounts of money. I would use a 30 weight like others mentioned.

 

[haks310]

I personally would stay away from the 20 weight oils, especially on a motor that doesn't call for it. It's too thin IMO to provide adequate protection. And I doubt that you would even notice a difference in mpg. We're talking tenths of a mpg difference. Some newer cars call for it because with the CAFE (Corporate Average Fuel Economy) requirements saving these miniscule mpgs multiplied over thousands of vehicles can save them significant amounts of money. I would use a 30 weight like others mentioned.

Ditto.

Synthetic 5W-30 and be done with it.

 

[Z15]

There is no such oil as the XL 0W-20. The only 0W-20 they have is a 100% PAO synthetic.

You can safely use the XL line of oils in high mileage vehicles providing they are in good mechanical condition but don't use the 0W-20 or 5W-20 as they are spec'd for Furds and imports. Use XL 5W-30 as GM recommends or even the XL 10W-30 in your climate.

<This Oil is the one to use>

You will not see any significant fuel economy with a 5W-20 oil. If you tracked it over 100,000 miles, you might see a gain but in tenths of mpg, if that.

I have many customers with high mileage engines running the XL 5W-30.

 

[Enem178]

No problems and switched at 80something.