switching to synthetic
Seasoned Member
Joined: Mar 2014
Posts: 352
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From: Los Angeles
Year: 1999
Model: Cherokee
Engine: 4.0
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Junior Member
Joined: Apr 2014
Posts: 74
Likes: 1
Year: 2000
Model: Cherokee
Engine: 4.0
Hey guys it's been a few days since my last post. I've been wanting to switch over my oil to rotella but not sure if I should go with the t5 or t6 and which viscosity? Our winters aren't so bad but can get to 0°. summers get a high as 90° but average around 80-90. What should I use for winter and what should I use for summer? Thanks in advance fellas.
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Junior Member
Joined: Apr 2014
Posts: 74
Likes: 1
Year: 2000
Model: Cherokee
Engine: 4.0
Thread Starter
Junior Member
Joined: Apr 2014
Posts: 74
Likes: 1
Year: 2000
Model: Cherokee
Engine: 4.0
Herp Derp Jerp

Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
It is. It's not so bad when it's summer but violates the engineering specifications when it's cold out.
T6 is the blue bottle full synthetic.
T6 is the blue bottle full synthetic.
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Junior Member
Joined: Apr 2014
Posts: 74
Likes: 1
Year: 2000
Model: Cherokee
Engine: 4.0
Alright, so I should be good running t6 full synthetic 5-40 all year round? What if I went with 5-30? Also would the synthetic find leaks just like it would with Amy other oil?
Herp Derp Jerp

Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
5w40 is fine for year-round use. If you can find 0w40 even better. 5w30 is also fine for year-round use.
The rate at which oils "find" leaks varies between brands and engines. I can't tell you from here if your engine will leak on a specific oil. Generally if you have a leak you should fix it instead of covering it up...
The rate at which oils "find" leaks varies between brands and engines. I can't tell you from here if your engine will leak on a specific oil. Generally if you have a leak you should fix it instead of covering it up...
Thread Starter
Junior Member
Joined: Apr 2014
Posts: 74
Likes: 1
Year: 2000
Model: Cherokee
Engine: 4.0
5w40 is fine for year-round use. If you can find 0w40 even better. 5w30 is also fine for year-round use.
The rate at which oils "find" leaks varies between brands and engines. I can't tell you from here if your engine will leak on a specific oil. Generally if you have a leak you should fix it instead of covering it up...
The rate at which oils "find" leaks varies between brands and engines. I can't tell you from here if your engine will leak on a specific oil. Generally if you have a leak you should fix it instead of covering it up...
CF Veteran
Joined: Nov 2009
Posts: 8,172
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From: The Republic of TEXAS
Year: 1998
Model: Cherokee
Engine: 4.0L HO






