The easiest way to remember mix ratio for 2 cycle oil for your truck is 1 ounce of oil for every gallon of fuel. So basically if you put 20 gallons of fuel in you need 20 ounces of oil. This will work out to about 128:1 ratio which is very safe to use! Just for information purpose. Cummins authorizes up to 5% of WEO (waste engine oil) to be blended into diesel fuel. Knowing this now you can add up to 1.75 gallons of 2 cycle oil for a 35 gallon tank. But I would only stick to using 2 cycle oil and mixing 1 oz of oil to 1 gallon of fuel...

I just did my first refill of the ULSD / 2 stroke... like the first time, I added a quart of the "Penzoil Premium Plus synthetic blend Outboard" tcw3 rated. I put in 24 gallons, so my ratio is considerably less the 128:1. 16 ounces in a quart, right? To get to 128:1 I would need to add a quart & a half... something to try in the future. The Penzoil was $12 at Wallys, the house brand SuperTech O/B 2 cycle engine oil (tcw3) was aboout $8. They only had the Pensoil multipurpose in pints. I bought one just to get the container. The first tank my mileage was ave 18.4 overhead, 18.8 hand calulated. I've never had more than 17.5 and was typically mid 16's.

First off... 1 quart = 32 ounces 1 pint = 16 ounces Mix ratio 128:1. (You need 1 oz of oil for every 1 gallon of diesel fuel pumped into the tank.)

I just did my first refill of the ULSD / 2 stroke... like the first time, I added a quart of the "Penzoil Premium Plus synthetic blend Outboard" tcw3 rated. I put in 24 gallons, so my ratio is considerably less the 128:1. 16 ounces in a quart, right?

So you need 24 ounces of oil to hold the 128:1 ratio. But since you added 32 ounces of oil you ratio is now 96:1 ratio which is getting a bit thick. That also why I figured out the ratio because a lot of people just add a quart to 6 gallons, 12 gallons, etc... Which make it too thick everytime. Then what happen is the MPG falls hard (12-15 MPG).

Mike, I've just found out that one of the stations I fill up at is biodiesel. I saw a sign on the pump about a month back when I was filling up the truck. The sign said, "May contain biodiesel". I emailed the company with some questions and they did respond to my questions. In a nutshell, they said, there is no law/mandate that says they have to disclose the amount (if any) of biodiesel in the fuel that they sell on the pumps like gasoline. They also said that it will normally run between 5-11%bio depending on price and availability!!! :o They put the signs on the pumps just to inform buyers of what they are getting. I wonder if any of the other stations/companies that I buy fuel from are mixing in some bio and not informing us???Anyhow, I've lowered the amount of 2 stroke oil I'm using since I found this out. It doesn't matter where I fill up at, I've just dropped the amount to 16oz per fill up. In other words, 1/2oz per 1 gallon of fuel or an approximate 256:1 ration of 2 stroke to diesel. Since I've done this, I've had the last two tanks in a row now that have averaged 19.6 and 19.5mpg respectively!!! :D These tanks do include about 1/3 of the miles towing my work trailer around from job to job. Each tank has gotten over 600 miles on it also. Not that I was getting poor mileage at the 1oz/gallon ratio, but I'm getting slightly better now!!! Just thought I'd throw that at you!!! By the way, the fuel station that had the sign on the pump is, Thorntons. Don't know if there are any out your way?? Take care!! 8-)

You might want to check out the BTU's thread then.... viewtopic.php?f=14&t=18

Thankyou for the correction... My memory hasn't been worth a d-mn since the MS... I did add 1 quart of the oil, which is the 32 oz. I'll try backing it off some next, instead of increasing it. Thanks, Russ

So you need 24 ounces of oil to hold the 128:1 ratio. But since you added 32 ounces of oil you ratio is now 96:1 ratio which is getting a bit thick. That also why I figured out the ratio because a lot of people just add a quart to 6 gallons, 12 gallons, etc... Which make it too thick everytime. Then what happen is the MPG falls hard (12-15 MPG).

I'm starting to wonder if 1 oz per gallon is too much for me. My mileage is in the crapper, right in the mid 14's and drops to high 12's pulling a 4K trailer. Do you think dropping down to 1/2 an ounce will still be effective?

Mayfair, fill out your signature so we can see what your truck has on it!! That'll help a lot!!

I just want to point out that the initial application of 2 cycle oil should be calulated on the full tank capacity (30 in my case). Once you have the concentration of additive in the tank, then you use additive based on the fuel added. This may be splitting hairs but if over (additive) oiled consistantly it would be possible to build up unintended concentrations. I'm just on the introductory phase of this so am going to be more knowledgeable as I proceed. Thanks all for this thread and good thoughts.Russ

I just want to point out tht the initial application of 2 cycle oil should be calulated on the full tank capacity (30 in my case). Once you have the concentration of additive in the tank, then you use additive based on the fuel added. This may be splitting hairs but if over (addative) oiled consistantly it wouold be possible to build up unintended concentrations. I'm just on the introductory phase of this so am going to be more knowledgeable as I proceed. Thanks all for this thread and good thoughts. Russ

Your right... The first dose should be based on the size of the fuel tank only if that tank is fresh diesel without any other additives in it. Then the 128:1 ratio should be applied from that point on... Thanks Russ... :thumbsup

Hi Mike, I have been reading about this subject for some time now, and I have decided to give this a try. On my first tank my mileage actually went down from about 20 to 18 mog. On my last tank I used Stanadyne and mileage went to 21 mpg. I just filled up today and added 1 qt of TCW3 scycle oil. Same fuel station and driving conditions.My question is does this take a few tanks to see a result ?

You cannot base a additive on a single tank! Just weather, driving style, loads, condition of the road, etc will effect the results. This is common to see some try it one tank and give up because the MPG fell the first time...

Take a look a my long time logs...

Now from 20K to 30K is PS or MMO usage... notice very flat...

Then I start 2 cycle oil at 85K notice little to no improvement... But I figured out my optimal ratio fgor the truck and BOOM! the graph shoots off at about 95K... So no... You can't judge it in one tank... Even notice I have my high/lows yet with 2 cycle oil... :poke

Mayfair, fill out your signature so we can see what your truck has on it!! That'll help a lot!!

Sorry about that, I just did it. I'm still gettin gused to things over here. On a side note, I just added an Edge Comp last night. Hopefully it'll help me get better mileage. It sure seems to be helping all of you guy's that's for sure.

OK. I will continue with 1 qt per fillup (28 gal) for a while and see how she does. :cheers Another question. I tow a heavy fiver (14000 lbs) and use a ramifier box for an little extra power. I believe this box raises fuel rail pressure to increase power. Do these type of modules pose a potential problem when used on trucks running diesel blended with 2 cycle oil ? I understand that long term use of these bozes can and do wear out the injector nozzels... 8| I will probably upgrade to stage II injectors and an SP62/14 turbo when the factory injectors are toast. By the way I have 105k on my rig...I am really looking to just increase the life of the CP3 pump by putting back the lubricity in the fuel that we should have. If better mileage comes with it that is a bonus. :burnout2

Actually you want 28 Ozs of oil for 28 Gallon fill up... :D

OK, I will try increasing to 1oz/gal... Thanks...

ok.. I have a 2008 Dodge 3500 (6.7 Cummins, 6-speed auto) 4x4 Duelly. <Unk. size tank> My wife has a 2005 VW New Beetle with the TDI. <14 Gal. Tank >Should our ratio be 1oz. to 1Gal of reg. diesel fuel?

ok.. I have a 2008 Dodge 3500 (6.7 Cummins, 6-speed auto) 4x4 Duelly. <Unk. size tank> My wife has a 2005 VW New Beetle with the TDI. <14 Gal. Tank > Should our ratio be 1oz. to 1Gal of reg. diesel fuel?

You shouldn't use 2 stroke oil in your '08. It's got all the emissions stuff that the 2 stroke could play havoc with. Besides, your truck was designed to run on ULSD!! Don't have a clue about your VW!!

For those that are using synthetic, when you read the gas application ratios the synthetic has 100:1 on the label, most of the dino only goes to 50:1 so my guess would be to duplicate Mike's work for the synthetic. It is easier to work up - just add for tank capacity for the next level of treatment. One quarter oz per gallon for a full tank at 35 gal tank is 4 1/2 oz.I have sent 100:1 gas with synthetic with the crew for the 2cycle stuff for 5 years with NO seisures, it runs the 4cycle stuff with no problems and since they go uot with a new 5 when they are scheduled I have had no problems with contaminated gas. Of course the 5 can coming back is always empty so if they left the cap off in the rain they will put it in their pickup. Not my problem except to have a fuel filter to take out to get them going agin instead of wasting 1/2 a day cleaning the water out of the mower, no screwups with the wrong fuel killing a chainsaw or string trimmer. It is just a point on mostly not needing additives for the most part.The point on fuel for diesel is that mine was designed for fuel with a 350 rating and the current 520 ULSD causes squeaks and complaints from the forward part of both of my pickups that the 2cycle quiets I tried a gallon of WEO the last tank for a calculated 18.04 which would be about the same as without but there were a couple of other changes - the camper rode the whole time with about 400# of tool in it and the rear tires were changed from 3/32nd tread 245's to 9/32 265's for a gain of nearly an inch in rolling radius. I haven't clocked it on the mile markers or GPS yet.For a reasonable repeatable run on fuel mileage with the way the tanks have vent room and so forth 1k miles is about the lowest number that has real relavance. That is without all the lab gear to help banish error.keydl