I had a question on the forum about a gas tank this week and it got me to thinking about which one is better metal or plastic. Most of my BIG REDS have metal tans but I do have a few plastic tanks including my daily driver 85 250ES. I see advantages and disadvantages to both so here is my opinion based on my experience.
Originality - If you are restoring to factory new or like the original look a metal tank is a must. All of the plastic tanks I have seen alter the look of the BIG RED. They just don't capture the correct shape.
Decals - If you want to use reproduction tank decal and you want them to stay on a metal tank is required. The decals do not adhere well to the plastic tanks.
Paint - You can lay down a nice paint job on a metal tank. Also the metal tank allows for bodywork so that you can fix those dents and dings and make it look smooth
Venting - The metal tank uses a vent that is built into the cap where the plastic tanks use a vent hose that sticks out of the top of the cap.
RUST - Need I say more. Most metal tanks were replaced by plastic tanks due to the tank rusting out and leaking.
Damage - If you are using your BIG RED for work it stands a god chance to get some dings and dents.
Won’t rust – Yep you can keep gas in the tank for many years and it will not rust through. Also no rust will be going through the carburetor and the engine.
Reasonably priced – A replacement plastic tank is a little over $100. A decent replacement metal tank (not rotted out) is about the same price if not more.
Flexible – You don’t have to worry about denting or dinging a plastic tank.
Look/style – The shape of the replacement plastic tanks are close to the original metal tanks but are different enough that they change the look. Most reproduction decals will not stick to plastic gas tanks. A big plain red tank does change the look of the BIG RED.
Vent – The caps for the plastic tanks use a vent hose. This is fine but changes the look as compared to the flush look of the cap on the metal tank that has the vent built into the cap.
Fading – If left in the elements the color of many of the plastic tanks will fade over time. Plastic tanks can be painted but the results typically don’t turn out as well as metal tanks.
For me choosing metal or plastic depends on what I plan on using the BIG RED for. If the tank is in really bad shape and cannot be repaired easily and I plan on using the BIG RED for work then I will go with plastic. For a restoration I will try to use a metal tank everytime. I am surprised how many times I bought a BIG RED with a metal tank that the owner said that they did not have the metal tank anymore. This surprises me since I have not run into many metal tanks that can not be repaired. Some I just choose not to repair due to the condition. So like many things the answer to which is better metal or plastic is “it depends”.