What is the best oil to fight fuel dilution?

[blackdiamond]

(1) What brands/types of oils are the most resistent to the effects of fuel dilution?

(2) Are there any particular additives that seem to be a benefit in the battle with fuel dilution?

(3) What is the effect of fuel dilution on the oil?

If my memory serves me, I'm thinking that a Polyol-Ester basestock is the best? Something like Redline?

 

[Merkava_4]

Quote:

---

(3) What is the effect of fuel dilution on the oil?

---

It thins the oil out, but why do you suspect you're having fuel dilution?

 

[Gary Allan]

PP allegedly handles fuel dilution well ..or so I've been told.

..but what engine or service is this that subjects your oil to fuel dilution all the time. There are some that allegedly have inherent fuel dilution ..but most can tune it out or clean it away.

Fuel dilution can exacerbate cylinder/ring wear.

 

[blackdiamond]

I have a Mazdaspeed 3 with Direct Injection Spark Ignition (DISI) 2.3L turbo engine. When I pull the dipstick there is a slight fuel smell (it has been the same since new and now is about 6,000 mi) and I have heard that DISI Audi's have had some fuel dilution issues. I have Mobil 1 in it currently and have considered Redline, but $9 per quart for 5,000 oci seems excessive.

 

[spOILEDrotten]

Every vehicle I've ever owned does the same thing. Just get a UOA to be sure. If you are worried, just use a nice 40 weight if you aren't already. You do have a turbo after all. Unless you take really short trips, I wouldn't worry.

 

[bruce381]

straight wt 1 vis grade heavier than you need.
bruce

 

[steve40th]

Curious too as I have lowe tension rings so I get blow by and my fuel gets black quickly. I use a quart every thousand miles and use Rotella 5w40 Synthetic.

 

[VeeDubb]

The double secret RLI RS4 Oil seems great with fuel dilution. See used oil analysis section.

Also, maxlife synthetic protected my engine well even though I had severe fuel dilution. The wear was the lowest I've seen on VW 1.8T engines with or without fuel dilution. But the oil was shot at 3900 so it needed to be changed. Here is the link:

http://theoildrop.server101.com/forums/s...ge=2#Post911350

 

[tripleM]

Quote:

---

Quote:

---

(3) What is the effect of fuel dilution on the oil?

---

It thins the oil out, but why do you suspect you're having fuel dilution?

---

What causes fuel dilution?

 

[mcrn]

I would imagine that a HDEO would be best at fighting dilution.

 

[va3ux]

Quote:

---

What causes fuel dilution?

---

Normal blowby is first. Next step up in the cause is the engine running rich overall, or perhaps a leaky injector(s). And a clogged or improperly operating PCV system compounds it. And as already mentioned, some engine designs just naturally cause more fuel dilution in the oil than others.

 

[R6j6B]

It sounds like you may be doing a lot of short trip driving - you may wish to consider a shorter oci .

 

[JustinH]

I have a 96 thunderbird racecar with a built 4.6L, vortech supercharged, with 42# injectors.

Its tuned a bit rich to keep the motor as safe as possible.

This motor would thin 10w30 mobil1 out within 1500 miles. I change the oil every 2000 miles in this vehicle.

I have switched to rotella synthetic 5w40 with very good results.

 

[va3ux]

Quote:

---

It sounds like you may be doing a lot of short trip driving - you may wish to consider a shorter oci .

---

That's a big one right there. I don't know how I could have forgotten to mention it. Thanks

 

[AndyH]

Get a UOA to see if you really have a fuel dilution issue. Just because it's a turbo and direct-injected DOES NOT mean that you will automatically have a fuel dilution issue.

 

[JohnBrowning]

Well if you are not going to fix the cause of the fuel issue then you better run the thickest oil you can for the ambient temps!!! While summer here I would be thinking 15W40,20W50 etc....When winter hits maybe a nice 5W40. By starting with a thicker viscosity you buy your self time. Fuel will lower the viscoity,flash point and HTHS of the oil and the TBN as well. The 5W40's and 15W40's are going to have about the best TBN you can start with and designed to handle a lot of fuel and soot. So I would probably go Delo 15W40 in the warm months and Rotella-T Synthetic 5W40 dureing winter. Try to drive onthe HWY as much as possable to cook off as much of the fuel from the oil as you can regularly! Long term bore polishing and corrisive wear is going to get you!

 

[bruce381]

fuel dilution is just that NO oil will resist thinning when mixed with a thiner (fuel) oil. only way to tolerate is a heavier oil otherwise they ALL will thin.
bruce

 

[Rotarydave]

Rotary engines encounter higher fuel dilution than piston engine especially with wear. Most owners use Catrol GTX or Havoline 10w40 or 20w50 and tend to use a 3K oci.

 

[Merkava_4]

Quote:

---

When I pull the dipstick there is a slight fuel smell

---

That's typical of all gasoline burning engines. You can have a dipstick smell like fuel and yet have a UOA showing .01% fuel dilution. There's really very little fuel in the oil typically; it's just that gasoline is so extremely volatile, a tiny amount smells like a lot.

 

[dcoyne78]

I believe that Terry Dyson has mentioned on another thread that Renewable Lubricants Bio-syn works well at resisting problems related to fuel dilution.