Should I Use Synthetic Oil In My Jeep Wrangler? (WARNING)

Changing your engine oil at regular intervals is the single most important task you should do. Timeous oil changes extend the life of your Jeep by protecting its engine internals better during startup and in harsh conditions. But what engine oil type should you use on your Jeep?

Regular oil changes at appropriate intervals as specified by your manufacturer are the key to engine longevity, not necessarily if it is conventional, synthetic blends, or full synthetic. The owner’s manual does not specify the use of conventional or synthetic oil for the engine.

One thing for sure is, that there has never been an engine that has failed directly as a result of using regular oil, blend, or synthetic oil. So before you select which oil type to use, there are a few important factors to take into consideration.

These factors are:

• Are you regularly driving in extreme conditions? (Extreme hot/cold weather conditions)
• Is cost a factor or do you simply want the best oil available for your Jeep?
• Does your Jeep have high mileage? (200K+ miles)
• What type of oil has it been using up until now?

Once you determine your Jeep’s operating environment and the other above factors, you are eliminating the need for either overly-expensive oils or you might need to invest in a more advanced oil for better protection.

Extreme weather conditions are a major differentiating factor when selecting oil. If you live in an area that experiences sub-zero temperatures, then synthetic oil with a 0W-30 rating is a better option.

• This offers protection from cold startup because it has a lower viscosity and additional additives that protect your engine in cold temperatures.
• Conventional oils are less expensive and do a good job of protecting your engine.
• Use a 5w-30 for harsh operating conditions and a 10w-30 for normal weather conditions.

The differences in Jeep owners’ opinions came about when the marketing and sales departments of Oil manufacturing companies, decided to start hyping certain types of oil and punting one type above another.

• Some people buy into the marketing information and choose only to use the best quality, highest grade, fully synthetic oil available, paying the premium price.
• Other Jeep owners claim to be using regular oil for decades and experiencing no problems AT ALL!

Synthetic Oil & Leaks

There are many reports of owners using regular oils in the jeeps without any hassle for many years, then later switching to synthetic oils, only to develop oil leaks.

After reverting to regular oil, the leak miraculously stopped, and the owner vowed never to touch synthetic oil again. Now, you can decide if that was related to the oil switch or not, I’ll just leave that there as an FYI.

Does Oil Brand Matter?

What we do know for a certainty is that the oil brand you choose makes little to no difference anymore, since all modern oils produced by major companies are fantastic. I’m sure we can all agree that brand name is rather down to personal preference.

• Nobody can prove one major brand is better than the other, it’s all a matter of opinion.
• Since the invention of multi-viscosity oil, it doesn’t much matter what brand or oil type you use.
• Just continue changing the oil and the oil filter every 3-5k miles (FSM stipulates 3k).

3000-Mile vs 5000-Mile Oil Change Intervals

There are two trains of thought when it comes to oil change intervals. On the one hand, we have a manufacturer who specifies an oil change interval of 3,000-5,000 miles. Many owners swear by 3,000-mile oil changes, yet others are happy to let it run to the 5K mark.

• There are marketing companies who aggressively punt the 3,000-mile oil changes, for obvious reasons.
• They use terms like oil discoloration, contamination, and oil breakdown to build their case.

Whatever side of the fence you are on, it’s ok. If I must offer my personal opinion here, I tend to agree with the shorter oil changes and oil service intervals. Then again I drive a high-mileage diesel.

The most important factor to remember is, that oil is the lifeblood of your truck and clean oil is the number one important factor in protecting your engine and its longevity.

• If oil costs per year are not a factor for you, then so be it, change your oil as regularly as possible.
• I don’t care what it costs me per year for oil changes.
• I changed my oil on every rig I’ve ever owned.
• Heck, I change my mind every 3 minutes too.

Let’s now look at what the main causes of oil degradation are, and why it’s so important to change your oil regularly.

Combustion Contaminants

There are so many contaminants that break down your engine oil.

Water (Cooling system)	Rapid Oil Breakdown
Coolant (Cooling System)	Rapid Oil Breakdown
Soot (Exhaust)	Gradual Breakdown
Acid & sludge (Exhaust)	Gradual Breakdown
Fuel (Combustion)	Gradual Breakdown

When your engine is operating, all these contaminants slowly break down the oil viscosity over time. The combustion by-products can slowly leak past valve guides, piston rings, and other seals which include acid particles, carbon, moisture, and partially burned fuel, which all contaminate the oil.

When oxidation takes place as a result of your oil coming in contact with hot engine components, these contaminants are formed.  Also, if your engine is using water and it mixes with the oil, rapid oil breakdown occurs.

• There are naturally occurring contaminants that mix with the oil
• The buildup of contaminants and breakdown of the oil is what you should be concerned about, more so than oil type or brand.

Regular servicing will reduce the breakdown damage and extend the lifespan of your engine. If your engine oil is clean, your Jeep will repay you with endless reliable miles with smiles.  Just don’t forget to change the oil filter too!

Best Oil for Jeep Wrangler

The best oil for your Jeep Wrangler is clean oil. Irrespective of the type of oil, it could be full synthetic or regular oil. What doesn’t or shouldn’t change is the oil replacement intervals.

It doesn’t mean because you are using a more expensive, premium oil brand, you can now extend the interval of your oil changes.

Sure, you can argue that synthetic oil, theoretically lasts longer than regular oil, however, synthetic oil still gets contaminated at the same rate as regular oil.

With that being said, oil change intervals should be the same for conventional and synthetic motor oils because of the reasons stipulated above.

Mopar recommends using six quarts of 5W-20 oil. Depending on your driving conditions (extreme heat/cold) you can also use 5W-30.

What You’ll Need For An Oil Change:

• 6 quarts of 5W-20 or 5W-30 (Weather Conditions Depending)
• New Oil Filter
• Ratchet
• 13mm Socket for oil pan bolt
• 24mm Socket for the oil filter
• Drain Pan
• Shop Towels / Paper Towels/cardboard

Does Jeep Use Synthetic Oil From The Factory?

Jeeps are filled up with Mopar 68218890AB 5W20 Engine Oil

This is regular oil and the same oil found in your engine when you purchased it from the dealership. If you were to have your Jeep serviced at the dealership they would use this oil.

The factory service manual recommends an oil change every 3000 miles.

This service interval is fit for the vehicle being used for:

• Off-roading
• Towing
• City driving
• Dry dusty conditions

It is not recommended to extend the service interval simply because you are using an expensive fully synthetic oil. The rate at which the oil gets contaminated is still the same. Stick to the Mopar recommendations.

FINAL THOUGHTS

If you do your research you’ll realize 3-5k mile oil changes are best practice. The oil service parts are so cheap in comparison to the related problems you’ll run into caused by heavily contaminated oil.