kurvy

Going to change the oil today and was wondering what type of oil should I be putting in?

248K Miles
'91 Jeep Cherokee

I was thinking about the Mobil 1 Synthetic, but what weight??

10W-30??

jd4x426

I use castrol gtx highmileage 10-30 in summer and 10-40 in winter i wouldnt switch to synthetic if you arent currently using it on a motor with that many miles you will have tons of leaks

patnok

I'm gonna say that my XJ is happily running along with the mobil1 high mileage 10W/30. I don't know when my brother (PO) switched but the literature expressly states that it is OK to switch over. From my understanding you can't "go back". Jeep has 225,000miles.

bishop letov

maybe I read that wrong? Wouldnt you want to put the heavier wieght oil in during the summer months?

kurvy

from what the advance guy told me, 10W-30 is what you should run in the summer

also, i am running on penzoil 10W-30

capndoodles

I am currently using pennzoil platinum full synthetic on my '98 with 140k

RICZR2

I agree with bishop... you should be running 10-40 in the warm weather and 10-30 in cold weather.....actually you can run 10-40 all year around unless you are in extreame cold.

bishop letov

In the cold the oil is thicker and doesnt break down as fast and it also takes longer for it to get into the tighter parts which is why when your rig is cold it has higher pressure then when it gets to operating temp.

I run 10w30 in the winter and 10w40 in the summer. The higher the weight the more fuel used. if its thick enough for me to wait for it to pour out of the bottle then just imagine what going on in 10* temps when you first start it in the morning. At colder temperatures it really gets as thick as sludge. Its one of the reasons they sell those oil pan heaters...

Oh I run castrol.. it leaks out of the rust holes in the pan even though I plugged them up with screws. Synthetic would be a waste and recently just put a new pan in.

a1racer

i run a 15 50 all year long in my area it is pretty hot here all year long and the jeep loves this stuff runs perfect and the oil gauge is good about 50 pounds when driving and 20 to 30 when at ideal

X-J

10-w30
#1 Royal Purple
#2 Mobile 1
#3 Castrol

Wix Oil Filter

after many engine rebuilds Synthetic is the way to go.

X-J

And wix filters, someone rember the link "not to use fram filters" ?

Bigclubs

It's all personal choice as to which oil and filter to use. I had an 80 CJ-7 and used only Quaker State and any brand oil filter I could find cheap. When it came time to rebuild the engine, the oil passages were squeekly clean. That was many, many years ago.

Today there are soo many types of oil on the shelf a person could go crazy picking an oil and filter.

The main factors are the age of vehicle, mileage, type of driving and HOW much you want to spend every 3000 miles. With 248K, I would stick to a High Mileage blend oil which has addatives for the seals and leaks. Going to a synthetic would cause leaking of good oil for nothing.

If you change the oil every 3000 miles and having 248K, standard oil would be the cheaper way to go. 5-30 or 10-30 would be the recommended weight according to the owners manual.

Like oil changes the manufacturers/retailers are pushing oil changes at 3000, even though some vehicle makes, state 5000 to 7500 miles between oil changes. Just like now they say alignments every 12,000 miles, transmission oil flushes 15-25,000 and ejector cleaning 25,000. This is all to get you into the shop and you leave with "Peace of Mind" that everything will run great for years to ocme.

The choice is yours, do you want to spend $15-20 to do it yourself with conventional oil or pay the local garage $30-60 for regular to synthetic blend. And thats 4 times a year. Starts to add up using synthetic.

Don't know where people get the idea you can't go back to regular oil from synthetic. You drain 95% or more of the old oil during a change. Also if mixing the two is so bad, why have they come out with a Super Blend using both types mixed together. In-between oil to satisfy both sides.

offroadnut36

you should use 10w-30. for oil brand, it doesn't really matter, but I only use Mobil 1 high mileage in my jeep. And never use Fram oil filters.

bajarunner

i am running on 10-30 the cheap one (it leaks anyway)350K miles and counting.........

XJ's~For~Life

Just like any other ride, I use Vavoline 10W40 year round. Hard to beat Valvoline Oil!