Can oil selection help fuel dilution?

[Indydriver]

My Mazdaspeed3 is a consistent fuel diluter, at least the way I use it (4 mi commute). My last UOA showed 2.8% fuel and viscosities dropped out of grade (although TBN was still 5+). I'll have to disagree with those who claim the human senses can't read oil condition--this one reeks of gas as soon as you pull the dipstick. After 3000 miles, the oil is black and has lost lubricity. I used conventionals (mostly PYB) for the first 22,000 miles with good results. OCs were at 1250, 2500, then every 3,000. I switched to PP three changes ago. I changed the oil this weekend after 4000 miles because the oil looked, felt and smelled trashed. I've always used the recommended 5W-30.

Obviously, I could go up a grade and I've thought seriously about M1 0W-40. But, I don't like the increase in cold viscosity and it's a higher ash oil which I've been reading is not good for DI deposits. Is there another oil I should consider? I'm not really interested in the ultra expensive boutique oils. If anything, I'm considering going back to conventionals with 3000 mi OCIs.

Another thing feeding my concern is a notice received from Mazda where they extended warranty coverage on the turbo and timing chain but went out of their way to point out that this coverage would only be honored where oil changes did not exceed factory recommendations and that oil used must not be less than 30 wt. My 30 wt oils are quickly diluted to less than that so I'm concerned about it.

So is it just wishful thinking that any oil can help this situation or should I just accept the short intervals? Recommended grade or a step higher? If this, what about cold starts and my chronic short trips? Stick with syn or go back to conventional?

 

[Eddie]

You don't mention wear value numbers which are the important issue here. I run PP5w30 in my 07 CX7 for 6K mile OCs and dilution runs ~ 1.5% I remember but, the wear values are good. I think if you can try to get a 10+ mile highway run in every week it will help much. Your nose is not a good indicator of how much dilution is in the oil. The aromatics in gasoline make a tablespoon in 5 quarts of oil smell like 50% gas. Ed

 

[daves66nova]

why would it have that much gas in the oil? Dumping too much gas out,running super rich?

 

[volk06]

Originally Posted By: daves66nova
why would it have that much gas in the oil? Dumping too much gas out,running super rich?

IIRC, that car has a DI engine. DI engines are notorious for fuel dilution.

 

[KCJeep]

Valvoline WB has shown good resistance to fuel dilution if you peruse the UOA section and it's not expensive either. If you're getting that much fuel perhaps VWB and OCI's on the short side would be the ticket.

 

[buster]

I'd considering using a 10w30 full syn. 10w30's have little viscosity index improvers and should hold up a bit better when fuel dilution is an issue.

 

[Indydriver]

Originally Posted By: daves66nova
why would it have that much gas in the oil? Dumping too much gas out,running super rich?

The CW around here would say the DI and short trips are the culprit, neither of which are going to change. MS3s are known to be tuned a little on the rich side.

 

[Indydriver]

Originally Posted By: buster
I'd considering using a 10w30 full syn. 10w30's have little viscosity index improvers and should hold up a bit better when fuel dilution is an issue.

This is a good point Buster although I'm a little hesitant to give up any cold start viscosity. This car is stored in a heated garage but will face one or two starts per day in bone cold Indiana winters.

 

[INDYMAC]

Take a look at LE 8531. I have seen it perform well in a VW GTI. V40C and V100C stayed right on the money through 7500 miles with high fuel. Very low wear too.

http://products.lelubricants.com/item/5w-30/monolec-tetra-syn-engine-oil-8531/8531?bc=100|1311|1312|1481&forward=1

 

[Phishin]

Originally Posted By: INDYMAC
Take a look at LE 8531. I have seen it perform well in a VW GTI. V40C and V100C stayed right on the money through 7500 miles with high fuel. Very low wear too.

http://products.lelubricants.com/item/5w-30/monolec-tetra-syn-engine-oil-8531/8531?bc=100|1311|1312|1481&forward=1


Here is the VOA I got for the oil....
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2718675#Post2718675

Although not widely used or even known about, those that do use it seem to really enjoy fantastic results.

 

[CATERHAM]

Originally Posted By: buster
I'd considering using a 10w30 full syn. 10w30's have little viscosity index improvers and should hold up a bit better when fuel dilution is an issue.

I've never seen any documented evidence that using a low VI heavier oil and therefore a thicker oil on start-up actually works in solving a fuel dilution problem. It may reducing fuel dilution slightly but it's much like running a much heavier oil to try and fix an oil leak; it won't but it may slow the leak at the detriment of proper efficient lubrication.

INDYMAC, unfortunately the real problem is the 4 mile commute and under such conditions the oil will not get up to temperature, hence the build up of fuel and condensation in the oil. Even diluted the oil will still be way too viscous due to the low oil temp's.
I'd run a cheap dino and change the oil frequently (before the TBN is largely depleted).

 

[Quattro Pete]

Originally Posted By: CATERHAM
INDYMAC, unfortunately the real problem is the 4 mile commute and under such conditions the oil will not get up to temperature, hence the build up of fuel and condensation in the oil. Even diluted the oil will still be way too viscous due to the low oil temp's.
I'd run a cheap dino and change the oil frequently (before the TBN is largely depleted).



^^^^^^ This!

 

[SHOZ]

Splice in a catch can inline with the PCV system. Mount it in a cool place. It will stop 90% of the yellow gunk.

 

[Brons2]

CJ-4 oils meet SM and have a max 1.0% sulfated ash. I'd try T6 if it were me.

 

[mechtech2]

Thicker oil helps with oil dilution.
Other drawbacks would then be present, but to specifically fight fuel dilution, thicker oil works.

 

[fdcg27]

I had 2.9% fuel dilution in my e36 with Nextgen Maxlife on a 4K run and wear was almost nonexistent, so it might be worth a shot.
Ester based oils seem to do well with fuel dilution, and G-Oil is pretty cheap, often FAR, so you might consider it
You do have options to consider.
What kind of wear did you see with 2.8% fuel?
If wear looked good, you might be worried about nothing.
Low wear with some residual TBN equals no worries.

 

[bourne]

I would do short runs on VWB. Look around for Goodyear/Sears coupons in your area. They use valvoline products. Depending on your area , an oil change can be had for under $20 pre tax. And I know at Goodyear, we use CQ Red/Blue filters made by WIX, so you are set there.

Short OCI might just be the solution for your fuel dilution issues.

 

[Indydriver]

Originally Posted By: CATERHAM

I'd run a cheap dino and change the oil frequently (before the TBN is largely depleted).

Thanks Caterham. This reinforces the direction I think I want to return to. The first six or seven OCs were with PYB on shorter intervals and it worked just fine. But if you drive any kind of turbo, there's a lot of hype that you really need synthetic to survive the occasional hot spots.

I do have a rather large stash of both PP and M1 5W-30 that was purchased for this car but I also have $2.08/qt Chevron Supreme which seems to be a good conventional.

 

[Garak]

Originally Posted By: Indydriver
Thanks Caterham. This reinforces the direction I think I want to return to.


He's definitely right. Thicker oil will accomplish something, but it's just a band aid (i.e. the 15w-40 summer fill in my old F-150 with massive fuel dilution). If you want the fuel out of the oil, you either need to get the oil up to sufficient temperatures or simply change it out.

On a related note, especially with the mention of VWB, is MaxLife SN/GF-5 down in the States? If so, that's another option. In the old truck, oil pressure stayed where it belonged for far longer using MaxLife 5w-30 versus any other 5w-30 PCMO. I could go through an entire OCI without the oil pressure light coming on, which wasn't possible with other 5w-30s I tried.

Besides, Merkava_4 gets ten cents each time we mention MaxLife.

 

[Indydriver]

Originally Posted By: Garak
If you want the fuel out of the oil, you either need to get the oil up to sufficient temperatures or simply change it out.

You know, I've read this a hundred times on BITOG and I'm wondering if anyone has actually proved this? It's not like my car is never driven over four miles at a time. A couple of weeks ago, I drove 120 miles a day two days in a row. I question the theory that you can drive fuel dilution out of the crankcase.