I get it that ideally you would want to run a tank of gas containing Techron / Gumout right before you change your oil - but what if that is not possible and you need to change the oil with 3/4th to 1/2 a tank of gas containing the fuel system cleaner in it ? In a well maintained engine , is there any problem with changing the oil while you still have a tank of gas left containing a bottle of Techron / Gumout in it ? In my case I used Gumout Complete fuel system cleaner .
Techron / Gumout : Use Only Just Before Oil Change ?
- Thread starter ChrisD46
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No issues at all.
The Gumout bottles recommend every 3,000 miles and not more that twice per OCI. So I use a bottle when my OLM is at like 55% and again when I'm a tank or two before an oil change. I think it's the over-cautious BITOGer who only uses it just before an oil change.
And where did this notion originate?
Is it pure myth or from a reasonable body of evidence?
seriously
The “use a fuel system cleaner in the last tank of gas before your next oil change” is found every where here and elsewhere . The logic is that any deposits removed by the fuel system cleaner will land in the oil which will be changed soon when the gas tank + fuel system cleaner reaches down to 1/4 gas tank… *My question is in a well maintained engine , often using top tier gas the likelyhood of fouling up oil with a high amount deposits SHOULD be limited ?
I prefer running it just before oil change but that doesn't mean I stick to this religiously. Why potentially contaminate fresh oil right in the beginning of an OCI?
I’ll use it 400 to 500 miles before my oil change a couple times per year.
Back in the days when Terry Dyson was on this forum, he recommended an oil change following my use of BG-44K.
Note: Dyson Analysis was a fixture in the oil analysis business for years
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Chevron used to make such recommendations right on the label, as well as warnings about excessive dosage.
Gasoline is already a pretty powerful solvent, but not enough to dissolve fuel deposits. The addition of another solvent increases the risk of oil contamination.
In practice, disregarding the recommended guidelines isn't going to lead to the end of the world. But this is purportedly a place where people are inclined to follow the best practices, no? (aside from brake fluid, that is)
I agree - I just found myself having to change oil at the 3/4th gas gauge mark after adding Gumout Complete to a full gas tank before a trip. At least I had 1/4th gas tank of the fuel system cleaner doing its thing removing feposits for a 1/4th gas tank before changing the oil . The engine is well maintained so probably no harm dond doing ig judt ghix ond time . Oil will be changed at 4,000 miles.
Well. I just changed my oil in my truck last week(posted filter C&P.) Today I added a bottle of Techron to the tank since I had to take my Camry to the shop and am now driving the truck for the week. Figured I'd push some gas and cleaner thru it since I'm driving it daily. Truck normally sees about 150 mi. per month when I use my car. Should I change the oil again next week when I get my car back???? Lol. Probably gonna drive 150 miles this week.
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- May 24, 2025
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Nope. Just relax and run the current tank down to E to rid the Techron.
Been doing this for eons. No engine troubles. Do the OCI, dump Techron in the tank at whatever the amount of gas is in it. Never had a problem. No reason to do it every OCI, maybe every 3 OCI's with some HEET red bottle, and maybe some CAT cleaner. The pump gas is garbage nowadays. Longing for the days of no ethanol. Still remember them. Now tailpipes are so black from that garbage, it's insane.
I recall this recommendation (from Chevron) was on the basis that some of the additive would get into the oil and “deplete engine oil additives”. The one thing I can find is that PEA will bind to ZDDP, so it would be less effective as an anti wear additive. Not sure what else might be affected by PEA or other detergent additives.
The gist would be to minimize the time that it’s in this state, in addition to removing as much of this “contaminant” in the oil.
Noted. Will run Techron prior to OCI. Thanks .
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