2018 Tundra flex

How do I tell if my engine is flex fuel I have a 2018 Tundra 5.7 381/401

 

Well it should be on the window sticker. I also believe it’s in the VIN somewhere. Somebody will come along and verify.

 

Look at the gas cap?

 

Call dealer, tell em your VIN #

 

Mine says it on the gas cap

 

Should say on the gas cap, but if you don't have the original one or it's no longer readable, you can put your VIN in here and it'll give you the specifics of your vehicle:
https://www.toyota.com/owners/vehicle-specification

 

Look at 5th letter of VIN...
W = FFV
Y = non-FFV

Found that with a quick google search. Verified mine has a W for my 5.7l FFV

This is from 2007, but verifies the 5th letter indicates engine type: http://www.tundraheadquarters.com/blog/decode-your-toyota-tundras-vin-number/

 

Is code still valid for 2018. I have a Y

 

Should be

 

Yup, it says it on the gas cap.

 

I tried this site and could not get an unstandable read on my 2017 DC.
Reading the code, my body style U is not listed. (?)
Does not mention that it is flex fuel but my cap says it is
Says I have a 26 gallon tank but I have a 38 gal.

 

I would make sure you entered the VIN correctly. I used it numerous times when I was truck shopping and had no issues. If yours isn't listed properly maybe something was added to the truck after the fact? You can always contact Toyota about it. They've been good about getting back to me when I have questions.

https://www.toyota.com/support/#!/app/ask