Unleaded in diesel truck

Asked by Jacob Jul 29, 2019 at 05:55 AM about the 2008 Ford F-250 Super Duty

Question type: General

About 10 days ago, I accidentally put less than half
a gallon of gas into my diesel truck (2008 f250), I
topped it off with about 18 gallons of diesel. So far
my truck seems to be running fine, will my truck
still be ok? Did the gas already dilute or burn?   

5 Answers

205,105

You should be fine, that small amount of gasoline mixed with what was still in the tank and what you added in on top of that really diluted the gas. I wouldn’t worry about it.

89,645

Gasoline in a diesel system is destructive in any amount over about 10% of the tank. Immediately, the gasoline will float and not enter the system, but in a short time it will be absorbed throughout the diesel fuel. This can cause pre-ignition which can lead to engine damage. Gasoline contamination can also damage the fuel pump and the diesel injectors, and as gasoline is a solvent it can corrode the entire system. BUT, a half gallon in 20, you should be OK. But I'd top off the tank each time it's half empty for a while.

2 people found this helpful.
13,445

You are in luck as diesel fuel is heavier (~7.1 lbs. per gallon) than unleaded fuel (~6.2 lbs. per gallon). So you are not having any issues as the unleaded fuel is floating on the diesel fuel in the tank. If you want to be absolutely sure you will not have any issues in the future, you really should have the tank completely drained. If the fuel level gets low, it may pick up some unleaded and send it to the engine (which would be bad).

271,765

You dodged the bullet this time. I would top it off with diesel to keep the gasoline diluted.

Your Answer:

F-250 Super Duty

Looking for a Used F-250 Super Duty in your area?

CarGurus has 902 nationwide F-250 Super Duty listings starting at $3,950.

Postal Code:

Ford F-250 Super Duty Experts

  • #1
    F_O_R
    Reputation
    3,170
  • #2
    Tracy Hooks
    Reputation
    2,050
  • #3
    NorCalEvan
    Reputation
    1,550
View All

Find great deals from top-rated dealers

Search

Related Models For Sale

Used Ford F-350 Super Duty
26 Great Deals out of 1,866 listings starting at $9,898
Used Ford F-150
264 Great Deals out of 12,426 listings starting at $3,695
Used Chevrolet Silverado 2500HD
20 Great Deals out of 1,485 listings starting at $6,750
Used GMC Sierra 2500HD
32 Great Deals out of 1,621 listings starting at $5,900
Used Dodge RAM 2500
67 listings starting at $7,595
Used Chevrolet Silverado 1500
115 Great Deals out of 10,428 listings starting at $4,330
Used GMC Sierra 1500
101 Great Deals out of 9,806 listings starting at $2,500
Used Toyota Tundra
22 Great Deals out of 1,334 listings starting at $7,995
Used Ford F-450 Super Duty
4 Great Deals out of 93 listings starting at $22,900
Used Ford Mustang
40 Great Deals out of 1,804 listings starting at $5,750
Used Dodge RAM 3500
56 listings starting at $14,999

Used Cars for Sale

2020 Ford F-250 Super Duty For Sale
160 listings starting at $47,579
2019 Ford F-250 Super Duty For Sale
5 Great Deals out of 285 listings starting at $40,995
2018 Ford F-250 Super Duty For Sale
57 listings starting at $27,888
2017 Ford F-250 Super Duty For Sale
8 Great Deals out of 101 listings starting at $32,988
2016 Ford F-250 Super Duty For Sale
4 Great Deals out of 65 listings starting at $23,000

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.