Walmart's cheapo oil is ~$14/5 quarts + $3.50 for an extra. They sell havoline full synthetic 6 quart box (like a box of wine) for $19.99. In searching they also have a dino box for $14.99.
What oil do you guys use on your 4.0s?
- Thread starter Rubirob
- Start date
17 isn't cold enough that I'd switch to synthetic. A 5W-30 conventional would be fine for those conditions.
Last edited:
Jeanfi007
Member
17 isn't cold enough so I'd switch to synthetic. A 5W-30 conventional would be fine for those conditions.
Thanks Jerry,
I drive the same way.
I use semi synthetic 10w40.
What do you think?
I'm not a fan of any viscosity other than what the engineers spec'd for our engines. In 55 years of driving I've never had an engine problem and I've always just used the viscosities the factory recommended.
I've only ever used two things in my Jeep. This filter and this oil. Because that's what I started with and knock on wood, have not had a problem with oil or engine trouble in 228,000mi
Jeanfi007
Member
I'm not a fan of any viscosity other than what the engineers spec'd for our engines. In 55 years of driving I've never had an engine problem and I've always just used the viscosities the factory recommended.
ok Jerry,
I will follow your advice and I will put 5w30
I just did my oil change today.
I wanted to switch to Castrol for this change as it is a premium oil, but couldn't find the Castrol GTX 10W30 synthetic blend (semi synthetic).
So, I disregarded all advise and went for Castrol Magnetic 10W40, I think it is full synthetic... (sorry)
My Jeep is a 2006 inline 6 (4.0 liter), and I have almost 220K miles on it (350K kms).
The average ambient temperature in the country i live in is
15 - 20 degrees Celsius in coldest winter
45 - 58 degrees Celsius in hottest summer and maybe more
I bought my jeep with less than 15K miles used different oils since then conventional, synthetic and semi synthetic.
My previous oil that i was running was 5W30 Synthetic blend.
My EOP was:
45 psi on cold start
32-34 psi on Idle (engine hot)
54 psi on 2300 RPM (approx 70 - 75 MperH)
Max Psi is 59 @ full race which i guess the capacity of the oil pump.
Today after changing the Oil to Castrol 10W40 magnetic (Full Synthetic), the readings are almost the same, but i still have to check the readings at cold start.
I am not a mechanic, and most of my knowledge comes from the internet and forums like this, but i have done a lot of work on my Jeep through a professional work shop owned by a close friend, and I enjoy watching upclose and asking him many questions
I wanted to switch to Castrol for this change as it is a premium oil, but couldn't find the Castrol GTX 10W30 synthetic blend (semi synthetic).
So, I disregarded all advise and went for Castrol Magnetic 10W40, I think it is full synthetic... (sorry)
My Jeep is a 2006 inline 6 (4.0 liter), and I have almost 220K miles on it (350K kms).
The average ambient temperature in the country i live in is
15 - 20 degrees Celsius in coldest winter
45 - 58 degrees Celsius in hottest summer and maybe more
I bought my jeep with less than 15K miles used different oils since then conventional, synthetic and semi synthetic.
My previous oil that i was running was 5W30 Synthetic blend.
My EOP was:
45 psi on cold start
32-34 psi on Idle (engine hot)
54 psi on 2300 RPM (approx 70 - 75 MperH)
Max Psi is 59 @ full race which i guess the capacity of the oil pump.
Today after changing the Oil to Castrol 10W40 magnetic (Full Synthetic), the readings are almost the same, but i still have to check the readings at cold start.
I am not a mechanic, and most of my knowledge comes from the internet and forums like this, but i have done a lot of work on my Jeep through a professional work shop owned by a close friend, and I enjoy watching upclose and asking him many questions
I'm not a fan of any viscosity other than what the engineers spec'd for our engines. In 55 years of driving I've never had an engine problem and I've always just used the viscosities the factory recommended.
Jerry, I agree with you about this topic, and many others, but there's always an exception. I had a 2000ish Volkswagen with a 2.0 gas engine. My local mechanic told me to use a very high viscosity oil, 20W-50 if I recall. The explanation was this is what the engine was designed for, but the lower viscosity was "recommended" for better fuel economy. I put 250,000+ miles on that car and averaged 30 MPG using the higher viscosity oil. Last I heard, the car was still running strong.
Raymund
TJ Enthusiast
What the service manual specified. That's why it is a Service Manual.
i just change oil in my 1999 Jeep Wrangler 4.0 and i use Motul 10W-40 engine runs so much smoother and seams to be performing better.
Potomus Pete
TJ Enthusiast
I am guessing its like "Ex-con - Motul".
Me, I been using Mobil 1 10-30 since 2004 and switched to the high Mileage a couple years ago. This last change a couple weeks ago I switched to 10-30 Pennzoil High Mileage. As has been discussed here. I also sent another sample to Blackstone.
I run Rotella 10W-30 in mine. Keeps my valves quieter than other oil, and it gets *cold* here (-20 in the winter), so I'm not going heavier than 10W. I've considered running Rotella 5W-30 in the winter, it's just so pricey for T6.
castrol 10w 30 dino has been my go to oil for over 40 years.
Potomus Pete
TJ Enthusiast
My Tacoma Prerunner that I put 299k on has had Castrol Syntec in it forever. Motor is perfect inside in every way
Pantera99
TJ Enthusiast
Oh no, every forum has the dreaded oil thread!! 😳 Valvoline Maxlife 10-30, I believe its semi-synthetic. Seems to have lessened the rear main drip a little. But isn't the saying, Jeeps don't drip they mark their territory?? 😂🤣🐕
Quaker State High Mileage 5W-30 full synthetic in my 2005. Don't know what oil the previous owner/quick lube used, but it always had lifter noise. The Quaker State has it silent again.