Switching to synthetic - 2002 Trailblazer

[Nick1994]

Time for an oil change on my grandparent's 2002 Chevy Trailblazer 4.2L I6, 111k miles. It's been 1 year & 5,700 miles since it's last oil change, OLM is at around 35%. I put about 90-95% of the miles on it every year. It has no leaks at all and it has only run conventional oil the last 7 years and 37k miles they've had it (with exception of this last year it has had Castrol SynBlend) 3k-5k mile OCI's since then, previous owner was my grandmother's sister who bought it new, she's meticulous so I know it was maintained well.

Now to the dilemma: I want to run synthetic in it because I'd like to just stick to once a year oil changes. The mileage could go up if we take it on road trips (900 mile road trip coming up in September).

Which synthetic to choose? I'm sticking with 5w30. I've got the list down to:

Mobil 1
Mobil 1 High Mileage
PP
Pennzoil Platinum High Mileage (Walmart website says they have it, I won't hold my breath)

So, whichever one on that list with the most votes gets the pick!

 

[Falcon_LS]

Skip the high mileage. Either Mobil 1 or PP will do great. If you can source Mobil 1 or German Castrol 0W-40, even better.

 

[bvance554]

I don't see the dilemma, other than you need to stop driving your grandparents vehicle so much. You said you were already changing it once a year, so why the drama?

 

[slacktide_bitog]

Even the cheapest conventional 5w30 can be used for the full OLM's suggestion or one year. Smitty's syn blend is often on sale at Kmart.

Napa Synthetic is $2.99/qt this month. It is rebranded Synpower.

 

[UltrafanUK]

Originally Posted By: Falcon_LS
Skip the high mileage. Either Mobil 1 or PP will do great. If you can source Mobil 1 or German Castrol 0W-40, even better.


Agreed, but the OP wants to use a 30 grade, although if the block is a bit worn (Higher oil consumption), there is a case for using an Xw40. No need to use an 0w30 in the Phoenix area, so I would look at the 5 or even 10w30's, BUT it's a good idea to check the oil finder or guide page of the engine oil company web sites to see which oil they think is best.

 

[Johnny2Bad]

There is no dilemma. Choose one from your list, and carry on.

 

[Falcon_LS]

Originally Posted By: UltrafanUK
Originally Posted By: Falcon_LS
Skip the high mileage. Either Mobil 1 or PP will do great. If you can source Mobil 1 or German Castrol 0W-40, even better.


Agreed, but the OP wants to use a 30 grade, although if the block is a bit worn (Higher oil consumption), there is a case for using an Xw40. No need to use an 0w30 in the Phoenix area, so I would look at the 5 or even 10w30's, BUT it's a good idea to check the oil finder or guide page of the engine oil company web sites to see which oil they think is best.


0W-40 was merely a suggestion. That said, there are zero issues running thicker oils in this engine. In fact, for export, GM specifies an ACEA A3 rated oil over GM6094M with viscosity ranging anywhere from 0w30 to 20W-50 depending on ambient temperature. A 5W-40 stands out as the "recommended" oil:

 

[Rat407]

You can run Walmart SuperTech at 5k oil changes and be fine. I change the oil on a friends 2002 Trailblazer like yours using conventional oil and he has 324k miles on it. All original drive train and just recently had to replace the radiator. Those things seem to be bullet proof.

 

[mrdctaylor]

My daughter has this exact car. She puts maybe 6000 miles/year on it and I change it yearly with conventional oil. I considered synthetic too, but given that it has run its whole life on conventional and the fact that she doesn't put a lot of miles on it, I've stuck with green bottle Quaker State 5W30. Runs great.

 

[BigD1]

Might as well go with the best Mobil 1. $12 rebate available too. If you don't want to fool around with rebates, then the NAPA synthetic would do. My last Mobil Spring rebate is quickly approaching 12 weeks, and no check yet.

 

[BrianF]

If you stick to the oil life monitor, which in mine does not gong me after a year use any decent conventional oil. Use a quality filter and carry on. You are not worried about cold starts so just run something cheap.

 

[FastLane]

Mobil 1 5W30

 

[CT8]

Why would you want to switch to syn oil? will there be below freezing starts? does the mfg recommend syn oil?

 

[Nickdfresh]

Flip a coin. But I'd also consider Quaker State UD Full Synthetic with the rebate. Or Havoline ProDS syn from Advance on sale. Everything I've ever heard is that 4.2L is a beefy tough engine that isn't picky...

 

[Nick1994]

Originally Posted By: bvance554
I don't see the dilemma, other than you need to stop driving your grandparents vehicle so much. You said you were already changing it once a year, so why the drama?
I'm sorry it offends you so much that I drive my disabled grandparents to the doctor, to my grandmother's nursing home, grocery store, to their friends/family, on road trips, and use it to tow my trailer to remodel their house in their car.

 

[HM12460]

Originally Posted By: Rat407
You can run Walmart SuperTech at 5k oil changes and be fine. I change the oil on a friends 2002 Trailblazer like yours using conventional oil and he has 324k miles on it. All original drive train and just recently had to replace the radiator. Those things seem to be bullet proof.





Hoping mine will last that long!