https://kdvr.com/news/local/asking-an-expert-does-your-car-run-better-on-a-full-tank-of-gas/
No.
Less fuel is lighter, lighter is faster.
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I am so cheap I wanted to carry the least fuel weight possible.
But must keep it full.
Gasoline weighs 6.2 lbs/gallon.
Our full tank is 106.6 lbs.
Wanted to remove the never-used back seat, but wife will not allow.
That would indicate that the ECM would adjust the engine tune to the amount of gas that is in the tank, so as far as I know, the ECM does not change the VVT, timing and fuel curves etc etc etc settings for the amount of fuel in the vehicle…
Now in the drag racing world weight breaks things, meaning the lighter the vehicle the longer the same parts will last.. Now with that being said as a rule of thumb, for every 100 pounds you remove from your vehicle you can lower your ET by 0.10 (a tenth) of a second.. That rule of thumb is more for lighter lower HP cars…
That being said, running your vehicle below a 1/4 tank of gas can be harmful to the in-tank electric fuel pump as it uses the gas for cooling, get it hot enough-long enough-enough times and it will kill the fuel pump.. Proof? the 2008 high gas prices and limited supply of gas at the stations, we saw more fuel pump failures then any other time in my working career, even low to high mileage vehicles that NEVER had fuel pump failures were killing fuel pumps, and it was all traced back to people only putting a gallon or two of gas in at a time and even running out… Also warrantied out more replacement fuel pumps than any other time, and it didn’t matter if aftermarket or dealer…
Me pretty sure I won’t get bored enough to read that article
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Perhaps you should be asking, “Does your car run better on an empty tank of gas…” The vast majority of new internal combustion powered cars have their primary electric fuel pump located inside the gas tank to keep it cool and prevent overheating. You probably should not be driving around with your gas gauge hovering over Empty to save weight for “better gas mileage…”
It is recommended to keep your gas tank at least one-quarter full to prevent damage to the fuel pump, which can overheat or suck up sediment from the bottom of the tank. Refilling around the one-quarter mark helps ensure longevity for your vehicle’s fuel system.
In the winter, to reduce condensation in your gas tank, you should keep the tank at least half-full, especially during cold weather. A fuller tank reduces the air space inside, which limits the amount of moisture that can condense and freeze in your fuel lines.
Now, if I had a long commute or lived in a rural area with fewer gas stations along my route, I would probably be filling up when the gas gauge hits half a tank…
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It’s a minor point, but this affects the weight distribution and thus the handling. It’s my understanding that BMW aims for a 50/50 distribution when the tank is full or nearly full.
We do know a clean car runs better​
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When I was a kid, a car wash in my town had a sign with those words prominently displayed.
Yes, but what’s the calculation? At 8 pounds/gallon, 15 gallons is 120 pounds, 3% of 4K. Part of the extra energy goes to acceleration, part to rolling resistance, but none to wind resistance, which dominates at high speeds.
Making it a different calculation for we dinosaurs with mechanical fuel pumps.
You did not ask for the calculation. You did a passable job.
What calculation? If you live in an area where condensation could build up and freeze blocking off the flow of gas to your mechanical fuel pump, then do not let the fuel level get so low that there is a chance of condensation would build up…
If you live in a remote or rural area where gas stations are far and few between, or you drive long commutes, then you keep your fuel tank on the fuller side… You never know when a power outage will shut down your favorite gas station or that small rural station did not get it supply of gas. And you never want to be driving long commutes depending on a service station being open when you need it or you are stuck in traffic on the freeway after the road is shut down due to weather or an accident…
I prefer to err on the side of safety… For instance, on Day-Two of the Iran War, I topped off all my vehicles before the price of gas went up…
Biggest oil reserve to be released to cut gas prices. Guess I do not worry about saving pennies for full vs low tank of gas. Half full is the time I think about getting gas. 3/4 full looking more seriously, gas light on (wife) stop and fill up soon.
That’s a temp solution. This conflict is going to last a LONG time. Expect gas prices to rise significantly over the next few months.
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Besides the reality that it’s a short term solution, it takes about 13 days before the release of oil from the strategic reserves actually hits the market. So, buckle-up kids, it’s going to be a rocky ride.
The volume released equals about 25 days of the oil volume lost.
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The US imports only about 4% of its oil from the middle east - mainly Saudi Arabia.
And Venezuela oil is coming to the US.
Supply won’t be an issue but the price of a barrel will have an effect.
Shut down 20% of world oil production and prices will continue to rise.
And we export about 1/3 of our oil. Most are under long term contracts.
As reported by U.S. Secretary of Energy Chris Wright, on 11 March 2026, the Department of Energy will release 172 million barrels from the Strategic Petroleum Reserve, beginning next week. This will take approximately 120 days to deliver based on planned discharge rates.
For those of you chomping at the bit for the release of the strategic reserves, relax a bit… The Strategic Reserves do not contain refined fuel, they hold emergency supplies of federally owned crude oil, not refined Gasoline and Diesel Fuel… Once they are released the crude must be refined and then distributed.
As of early 2026, The Strategic Reserves held approximately 400 million barrels. This crude, consisting of both sweet and sour types, is stored in 60 underground salt caverns across four sites on the Texas and Louisiana Gulf Coast.