oil weight

[Johnson110]

i have a question have a jeep 4.0, currently using 10w-30 oil, wanted to use 10-40 oil for warmer weather, how would this affect gas mileage also heard that its not advisable to use heavier oil due to sluge bulid-up, 1994 jeep got it w/ 110k miles now has 128k miles change oil no later than every 3k miles, using purolater oil filters and walmart oil! thanks for any input.

 

[Boomyal]

Re: oil weight

Oil weight has no bearing on sludge. Sludge is caused by a build up dirt caused by unfiltered combustion by-products often exacerbated by moisture build up in the crank case. Clean, modern oils have detergents and dispersants in the oil that help keep the small particles in suspension so that they are filtered out before they are allowed to settle and accumulate as sludge deposits.<br /><br />Your choice of oil is determined by a number of factors, such as heat, load and machining tolerances. Many of today's engines are more tightly machined than in the past and require lighter oils. Lighter oils lubricate quicker, carry off heat better and produce less resistance allowing for better efficiency. It is best to conform to the manufacturers recomendations when you chose your oil weight. Most will allow for a range of choices depending on the temperature and load that you encounter.

 

[jimchere]

Re: oil weight

Stick with a good quality 10w-30. Jeep recommends this oil for the 4.0 I-6 even in hot climates. You're in NY, so I definitely wouldn't see the need for 10W-40 and if anything it isn't as good on those cool mornings, IMO.<br />I've had mine since new, and it now has 90k. Its been driven in TX, IL, FL, RI and cross country in all types of weather and my oil pressure has always been great. Motor has tight compression and I ran a borescope inside the oil fill cap up into the valvetrain (never had a reason to remove the valve cover) and its clean as a whistle, absolutely no sludge or gunk. I've been using pennzoil 10w-30 with oil changes at 3-5k miles and either bosch or purolator filters.

 

[LubeDude]

Re: oil weight

Boomyal: You are correct in everything you said, (as usual).<br /><br />Ok, I follow an oil analysis forum quite regularly and the best wear #s for the 4 liter jeep are with a 40 weight oil, as a mater of fact, although a great engine, the wear #s with a 30 weight oil are sometimes a little scarey even with synthetics. Ring wear and bearing wear are higher than they should be on an average. Even so, they go a long time. The recommended oils of choice for the 4 liter Jeep are HDDOs (Diesel oils) Id reccomend either Dello 400 15W-40, or the Penzoil Long life 15W-40, You can continue to use the Super Tech oil filter though, Its better than a Fram. Seeing you live in New York, Id change back to a 5W-30 in the winter though, as long as its not getting below freezing on a regular basis, youre ok with the 15W-40!<br /><br />Sludge problems have occered with 10W-40 oils due to the viscocity improvers needed to span the 30 point spread in 10W-40 oils, not a problem with synthetics, Some manufacturers will void your warantee if they find out you were using 10W-40 oil!

 

[Boomyal]

Re: oil weight

Originally posted by LubeDude:<br /><br />Ok, I follow an oil analysis forum quite regularly and the best wear #s for the 4 liter jeep are with a 40 weight oil, as a mater of fact, although a great engine, the wear #s with a 30 weight oil are sometimes a little scarey even with synthetics.

LubeDude, what does your forum say for wear #'s on a '94 Chibby 454? I'd be curious. I bought it at 17k mi and now have 40k mi's on it. I've been running 0w-30 U know what in it since I've had it. No extra heavy loads, other than it's own weight plus occasionally my medium weight 20 footer. Oil consumpsion is next to nil with pressure fine. As usuall only change the oil filters and top it off.<br /><br />JB

 

[LubeDude]

Re: oil weight

Boomyal:<br /><br />I researched the 454 and they like a 40 weight also, In this Pacific Northwest climate the oil of choice would be the Diesel Marine 15W-40 In the you know what brand! Im putting it in my Ranger at the next change.

 

[Boomyal]

Re: oil weight

LubeDude, you sure about that for a late model, low mileage 454. I can whip some of that 15w-40 Liosma out of my marine locker but I think that is heavier than the manual calls for in dino oil.<br /><br />What does this site do, Run different oils in an engine then analyse the oil for metal?

 

[LubeDude]

Re: oil weight

Using the 15W-40 isnt going to hurt a thing, the ratings are more for the vehicles Cafe ratings (FuelMilage) Than for engine protection! Beleive me, I wouldnt tell you to use something that would harm your engine. You could always go to the You know what Tech line and ask them what they think. This is what an oil analysis looks like. This was not done through an Amsoil Lab.<br /><br />Oil Analysis for Amsoil 10w30 on a 2000 Silverado 6.0 L<br />Time on Oil = 5126 <br />Time on Vehicle = 39740 <br /><br />Iron - 9<br />Chromium - 1<br />Lead - 12<br />Copper - 65 -------------> *Abnormal* <br />Tin - 0<br />Aluminum -3<br />Nickel - 0<br />Silver - 0<br />Silicon - 9<br />Boron - 1<br />Sodium - 3<br />Magnesium - 354<br />Calcium - 2639<br />Barium - 0<br />Phosphorus - 1002<br />Zinc - 1283<br />Molybdenum - 3<br />Titanium - 0<br />Vandium - 0<br />Potassium - 0<br /><br />Fuel - <1<br />Vis @ 100C - 11.99<br />Water - 0<br />Soot/Solids - N/A<br />Glycol - NEG<br /><br />TBN - 6.18<br />OXID - 21.0<br />NITR -17.0 <br /><br />The figures are Parts per million<br />It would take too long to explain every one and what is normal, but these are good #s. The TBN started at 12, but is still servicable after over 5,000 mi. The copper is high, but this seems to be normal for GM engines with oil coolers!

 

[Boomyal]

Re: oil weight

L'dude, I ought to get one of those done on my '97 4.6L Ford Van Motor. Never changed the 0w-30 since I put it in 163,000 miles ago. I bought it new. It has a 6600 lb GVWR and carries between 7400 and 8000 lbs daily. It currently goes thru about a quart in 4000 mi. Oh dang, it has gone thru three rear axle shafts. (inner axle bearing races are the axle itself)

 

[LubeDude]

Re: oil weight

Here is where to do it for $20.00.<br /><br /> oil analysis