Power loss with Lucas UCL?

[Craig in Canada]

I've just tried Lucas UCL in my last "fill up". It wasn't really a fill up, it was a topoff (between 10-20L) with enough Lucas to treat the whole tank (70L). My vehicle has dual fuel tanks and a transfer pump, I think that enough mixing has probably taken place. It would have been ideal to fill closer to empty, I know, but...

At any rate, I would say that it seems possible that higher RPM operation is a little smoother/quieter, but I feel like the car is down on power. I would include bad tank of fuel in my list of possible causes but I only replace 1/7th of the tank so that's probably not it.

I will be examining my mileage on a highway trip tomorrow. My FP60 and LC20 arrived today, but I can't try my FP until I've got the Lucas out of the system.


Craig.

 

[Rodbuckler]

I found that the recommended 1:400 is too rich. My fuel injected engines tend to be a little hesitant at lower RPM and slight throttle angles with that mix. My carbed engines are OK with it. 1:600 to 1:750 seems to work best, and doesn't try to bare the piston crowns.

Also, it took at about 10 tanks to clean up one of my higher mileage fuel systems. The engine ran OK, then worse, then better, then best ever. I really like the product.

 

[Craig in Canada]

Interesting. So if using Lucas UCL, mix less than recommended. In my case I'm actually a little more than recommended. The tiny "trial" bottle says it treats up to 95L and I put not quite all of it into 70L. I'll keep that in mind if I try it again.

I don't expect that my fuel system is particularly dirty, I'm just interested in trying things that other people have had great success with (not that the label says is great). Cleaner is always better, and some of the reported benefits of a fuel lubricant attracted my attention.

What's the negative angle of "bare the piston crowns"? I assume this is agressive cleaning removing all carbon? How could this be bad? Please educate me...

Maybe I'll go get more gas in this tank (used 20-25L out of 70) and see if that changes anything.

Craig.

 

[Craig in Canada]

Oh, I intended to report on mileage. It was quite windy today, but I did a round trip in four hours so it might cancel out.

My mileage is not up, it might be down a hair. My engine seems to feel both slower (at part throttle angles like Rodbuckler said, actually, although I made that observation before reading his message) and impessively fast high-rev WOT once or twice when passing.

Hmph.

Craig.

 

[Rodbuckler]

I think that 1:400 doesn't give a good mist out of the injector when the cycle is real short (low power). I bet the 1:400 works perfect in a diesel. And it seems to work fine in the carbed engines since the fuel/air emulsion is shredded violently when it comes out of the transfer slot at part throttle. 1:400 seems to work fine at full-throttle in everything I've run it in.

I haven't noticed any MPG increase, but have noticed reduced oil consumption.

The best condition for the piston crown is a thin hard layer of carbon. This acts as a thermal barrier which increases engine effeciency, and reduces heat soak into the piston at the same time. Just read the lip of the spark plug if you can't look down onto the piston crowns through the plug hole. Wipe the plug lip across your finger. Nothing appreciable should wipe off. Wet means oil, and fluffy dry means too rich.

 

[GT Mike]

Boy, I sure dosed the crap out of my Durango then! I dumped better than 2/3 of a quart of the stuff into 25 gallons of gas this afternoon!

I figured that the recommended 3 oz. per 10 gallons wasn't going to do much, so I did a little less than triple that.

Now I read this!

Oh well...I'll live with a little power loss and squeaky-clean injectors and piston crowns. Maybe I'll run a little of this super-rich mix out with some straight gas...I'll see how things go.

 

[Rodbuckler]

I don't think that it will clean any better with a megadosage. I think that it just takes a combination of time and the mild dosage. Then continued use keeps everything clean and lubed.

 

[Craig in Canada]

quote:

---

Originally posted by Rodbuckler:
I think that 1:400 doesn't give a good mist out of the injector when the cycle is real short (low power). I bet the 1:400 works perfect in a diesel. And it seems to work fine in the carbed engines since the fuel/air emulsion is shredded violently when it comes out of the transfer slot at part throttle. 1:400 seems to work fine at full-throttle in everything I've run it in.

I haven't noticed any MPG increase, but have noticed reduced oil consumption.

The best condition for the piston crown is a thin hard layer of carbon. This acts as a thermal barrier which increases engine effeciency, and reduces heat soak into the piston at the same time. Just read the lip of the spark plug if you can't look down onto the piston crowns through the plug hole. Wipe the plug lip across your finger. Nothing appreciable should wipe off. Wet means oil, and fluffy dry means too rich.

---

Interesting insights, thanks. I'm definitely going to top off the fuel tank and see what I notice. Do you have any first-hand observations with the behaviour of FP60?

I don't have any oil consumption - so I won't notice an improvement there

On the piston coating, I suspect that your point of view only applies to engines that do not have oil jets specifically cooling the underside of the pistons, correct? If your engine specifically cools the pistons, then optimum conditions would be squeaky clean (?).

Craig.

 

[Rodbuckler]

quote:

---

Originally posted by Craig in Canada:
definitely going to top off the fuel tank and see what I notice. Do you have any first-hand observations with the behaviour of FP60?
On the piston coating, I suspect that your point of view only applies to engines that do not have oil jets specifically cooling the underside of the pistons, correct? If your engine specifically cools the pistons, then optimum conditions would be squeaky clean (?).

---

I have never used the FP, but I plan to in the future. I was using MMO and ATF to some extent in the fuel in my 4-strokes before I started studying this forum. I was trying to emulate 2-stroke outboard oil performance in my 4-strokes, since my outboards always show so little wear and are clean. There's nothing like using the correct lube for the job!

I don't think that piston cooling from a dedicated oil jet eliminates the need for a piston coating. Both should help. The light carbon layer should be on the piston crown, chamber, and face of the intake valve. It should not be on the top of the first ring or groove, or on the valve seats or backs. The entire exhaust tract should be coated except the cat cores, but the exhaust valve is generally a different color.

 

[Craig in Canada]

Update:

The 155mL bottle says "treats up to 95L". The 1L bottle says to "add 100-150mL of UCL to 50L of fuel".

The wee bottle's ratio is up to 612:1 (not 400:1).

The 1L bottle's ratio varies from 333:1 to 500:1.

I noticed power loss with ~150mL in 70L of fuel which is 466:1.

I topped up with another 25L of fuel, no additional UCL. My 45L of remaining fuel had 45/466=95mL of UCL in it.

My new ratio is therefore 70/.095 = 736:1

It still doesn't feel right - less responsive, less part-throttle power, but I only have 25km on the top-up tank. I do have ARX in the oil right now, I suppose that it could have co-incidently changed "something" at exactly the time I added UCL but I kind of doubt it.

Fuel is Shell V-Power 91 from the same station almost every time all year.

Any other comments or experiences? After I run this tank down I'm going to try FP60 and see what happens. I find myself wanting to like UCL better, particularly since I can get it off the shelf here in Canada instead of all the hassle and expensive of getting FP across the border.

Craig.

 

[surfstar]

Too many variables right now for you to isolate it. I think you should wait until after your ARX treatment, or at least the clean phase, is over and then try again.

 

[Craig in Canada]

While it's true that ARX could be interfering, up until this point the car was getting stronger and had levelled off. I noticed the change within 5-10 minutes of adding UCL. I really doubt it's the ARX, but it is possible.

Craig.

 

[Craig in Canada]

Update: another 20km down the road after the top up and I think part throttle response has picked up again with 736:1.

 

[unDummy]

I've dosed ~100:1 in several vehicles with no power loss.

 

[Craig in Canada]

The UCL is out and the FP60 is in.. We'll see what happens.