Wrong oil
Thread Starter
JK Enthusiast
Joined: Oct 2007
Posts: 228
Likes: 0
From: Katy, Tx
Wrong oil
A buddy (NOT ME) put 10w 30 Mobil 1 in his JK on the second oil change instead of 5w20. Said it is OK because we are in Houston and it is hot out. He pulls a small boat on the weekends. Will this cause any damage or is he right that it is OK to do?
JK Enthusiast
Joined: Sep 2006
Posts: 164
Likes: 0
I think the "thicker oil is ok in hot climates" logic doesn't really apply anymore... I've also heard the argument that the thinner oils are loaded with additives which is bad. I just stick with whatever the engineers that built the vehicle specify... I figure that know what they're doing. 
Thread Starter
JK Enthusiast
Joined: Oct 2007
Posts: 228
Likes: 0
From: Katy, Tx
Heh, I dont think it was by mistake. I got to his house as he was filling it, he said he knew it was the "wrong oil", it was all they had at the parts house. He seemed to think there was not enough of a differance in the 5w 20 & 10w 30 to matter. I didnt argue with him since I dont know, but said I would post it here to see what the experts had to say.
JK Enthusiast
Joined: Apr 2008
Posts: 410
Likes: 0
From: Burning-Ham, Alabama
His Jeep, his choice of oil, his problem if there is a problem.
If it were my Jeep and I knew there was the wrong oil in it, I would not freak out, I would be ok with driving it some, but I would drain the oil and replace with correct type as soon as convenient. I would not bother removing the filter though, just drain and re-fill.
If it were my Jeep and I knew there was the wrong oil in it, I would not freak out, I would be ok with driving it some, but I would drain the oil and replace with correct type as soon as convenient. I would not bother removing the filter though, just drain and re-fill.
JK Enthusiast
Joined: Oct 2007
Posts: 277
Likes: 0
From: NC
I like the whole protect your engine idea, but I stick with the factory specs myself. I think it will be O.K. I mean 5-10 is not huge gap, and 20-30 is not the big dealbreaker either, I would just to be safe stick with the 5-20. i for years used 10-40 in everything, then when Mobil put out the new 5w-40 I jumped on it b/c it offered a new thicker when running oil that was fully synthetic. They have since pulle dit and re named it Diesel Performance or something. It used to be called Truck and SUV. I stick with Mobil and have had very good results. JOE>
Trending Topics
JK Jedi
Joined: Feb 2008
Posts: 7,215
Likes: 10
From: Georgia
That won't happen... Lets be for real... You can pour any oil you want in the engine and it is not going to cause it to fail. The engines are not that finicky. In fact, the oil you are dumping out of your engine (when you change it) are a different weight than what you put in just from the heat, stress, and breakdown of the oil. (of course, that is why you need to change the oil regularly). The most demands on the engine are at start up, which is why they use the lower weight oils to begin with.
You mis read my post. I didn't say the different oil would be the CAUSE of anything. I simply said IF there was an engine failure....for WHATEVER reason. If they find the wrong oil in the engine, they'll try to slink out of it.
JK Enthusiast
Joined: Aug 2008
Posts: 156
Likes: 0
From: Knightdale NC
i agree with using what is recommended, but ido understand that it was all the dealer had, i had a hard time finding 5-20, had to go 2 three stores to find it ended being walmart (moble1) always ran Q truckand suv in my 01 ram but Q in 5-20 here is not to b found
JK Enthusiast
Joined: Aug 2008
Posts: 106
Likes: 0
From: Texas Hill Country
I agree with sticking with the 5-20 for waranty's sake but 10-30 will not hurt the engine one bit. I ran 10-30 or straight 30 wt in every vehicle I owned pre JK - all the oil change place down the road they put 10-30 in my truck even though it said 5-30 or 5-20(don't remember)