How much oil should I be using?

packman35

Petty Officer 2nd Class
Joined
Jul 21, 2008
Messages
113
I have a 1993 Evinrude 115TLET with VRO. I am wondering how much oil I should be using. I tend to run 50% WOT and 50% 1/2 WOT (cruising @ 4000 rpm). I have maybe 10-15 hours total use so far. In this time, I have burned maybe half a gallon of oil from the oil tank. Is this normal? I know it is getting oil because when I start I get the nice blue cloud. My VRO alarm is currently not working (on my list of things to fix) so I want to make sure I am not doing any damage without knowing it.

Thanks.!!
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,320
Re: How much oil should I be using?

How much fuel have you burned? You should be burning roughly 1 gallon of oil for every 50 gallons of gasoline.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: How much oil should I be using?

Reminds me of a war I got into with some engineers when I was writing Service Manuals for their products.

The subject was the adjustment of tension on a gilmer belt. The Engineer's notes said "tight enough but not too tight".

So. . .you should be using enough oil but not too much.:D

Enough will come out to close to a gallon for each 50 gallons of gas, as dingbat said.
 

packman35

Petty Officer 2nd Class
Joined
Jul 21, 2008
Messages
113
Re: How much oil should I be using?

I never let the gas tank get too low so it's hard to say exactly how much I've burned but I would guess that around 50 gallons is a good estimate. I guess with the oil that was in the oil tank when I got the boat combined with what I have burned comes out to 3/4 a gallon or so. So I guess I am doing OK.

Thanks for the responses!!
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: How much oil should I be using?

The way to determine if the VRO is working properly is to place a mark on the oil tank where the oil level is right now. After you've run about 12 - 18 gallons of fuel add oil to bring the level back up to the line. With 12 gallons used you should need one quart of oil. With 18 gallons 1-1/2 qts. That ratio comes out to 50:1 or one pint for every six gallons of fuel burned. During the test, keep an eye on the oil level to make sure it is dropping. Add oil with the boat in the same attitude as when you started the test. Tilting the boat more or less will alter the oil level enough to skew the results.
 

packman35

Petty Officer 2nd Class
Joined
Jul 21, 2008
Messages
113
Re: How much oil should I be using?

Great idea!!! Thanks!!!

Quick question though - doesn't the ratio change depending on engine speed and/or load? Or would it just even out to be about 50:1?
 
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