Recently spoke with some old school car techs who swear by top cylinder lubes "added to the fuel tank" The explanation I got was that lube in the top cylinder "above the rings" can increase performance and FE. While browsing the local pep boys I came across top cylinder lube made by Lucas. It sounds good to me, what do you guys think. At 4 bucks per tank, it does not seem like a wise investment. In my case if I got 2mpg more, I would break even..

It's snake oil for the most part. It might be effective as a once-in-awhile treatment to keep things in tip-top shape, but unnecessary.

One gallon of gas - $3.49

One used four wheel drive SUV that gets 30+ Miles Per Gallon - $15,999

Purchasing it used for $5000 UNDER bluebook because the dealership did not realize it was a hybrid - PRICELESS

I would recommend testing it in a portable generator, $600-1,200, before putting it in my $25k car. Of course you could give it as an anonymous gift to someone at work with a card:

Congratulations!

You have been chosen to test this advanced fuel additive for free if you will simply test it with two tanks of gas (see enclosed gas card.) All you have to do is run one tank without the additive and record the total miles and then run a second tank with the additive and report the results when we call you in 30 days ...

Yes, it is a cruel world.

Bob Wilson

Operation Iraqi Oil Freedom:

Automatic, stock, project car.

My other 1500 cc car:

Automatic, stock, backup car.
Free speech, dialog and knowledge thrives without the poison of SPAM.

Too late, already had put the oil in. I have tried similar products in past years in non hybrid vehicles with no ill effects. May as well report my findings for whatever they are worth. First I noticed that at highway speeds exceeding 55 miles per hour, I am able to maintain around 45 mpg (normally highway means 39-40 mpg for me.) At lower speeds between 40-55 I notice less power and possibly a slight loss of MPG. Kind of washing out the positive. Again the increasing FE might just be the placebo effect and probably it is just the better FE for warmer temps. Yesterday after a 3 hour dinner and show, I proceeded to leave the restaurant and the ice did not turn on, I got worried and accelerated aggressively just to make sure nothing was wrong, I am starting to love warmer weather in my hybrid.

I wonder if this "top cylinder lube" is similar to 2 stroke oil? If so 2 stroke oil would be cheaper......

My guess is that "top cylinder lube" could only be sold to someone who had never pulled down an engine with 100,000 miles and looked at the cylinder wear pattern. The top of the cylinder doesn't wear. Especially with modern ring and cylinder metallurgy.

Ah, good point but I don't think that the product is marketed to prevent wear on the top of the cylinder as so much as to provide lubrication for the top stroke and exhaust stroke. If there was a benefit I'm sure the gas companies would have already added and marketed it at a premium cost to us.

I hear top cylinder lube may be coming back for those who would like to use ethanol blends in non-flex fuel vehicles.

Top end lubes helped remove carbon deposits than modern TOP TIER fuel already have as an additive. They are no longer needed IMHO, unless you insist on running spot market fuel.

Ducit Amour Hybridae
Mark Smith
Master Certifited Technician
Tempus non reparabilis fugit
"It isn't pollution that's harming the environment. It's the impurities in our air and water that are doing it."

Best Tank 35.0 MPG

Marvel Mystery Oil is one one of the most common of the top cyl lubes.You don't need it.Your motor won't break if you don't use it.Your vehicle -and most other vehicles will become scap for some reason than engine failure.
Worse case it might slightly foul your plugs, but I doubt that.
In the "old days" when a car engine was near done at 80,000 miles, it probably made sense to add lube every way you could.These top lubes are holdovers from another time.
Charlie