Does a 5.7 Hemi need premium gas?
5.7L Engine (With Automatic Transmission)
This engine is designed to meet all emissions regulations and provide satisfactory fuel economy and performance when using high quality unleaded gasoline having a posted octane number range of 87 to 89 as specified by the (R+M)/2 method.
The higher the compression ration of your vehicle, the higher the horsepower. This is why high-performance engines require more octane. If you have the HEMI V8 engine, you should use the 89 octane, if you have the base V6 engine, then it is okay to use the 87. Just never use higher than 89!
No, mixing regular gas with premium gas in your fuel tank will not damage your vehicle. And, contrary to popular belief, adding premium gas to your regular gas won't add any extra power to your engine either.
"You should use whatever octane fuel is recommended by your manufacturer." The HEMI is 10.5:1 compression ratio. 89 octane fuel is recommended for optimum performance and fuel economy by Mopar. Gasoline with this octane number is proper for engines with compression ratios of 7:1 to 9:1.
27 MPG in a RAM 1500 5.7L HEMI - YouTube
If your car doesn't require premium, fill up with regular.
In a consumer notice, the Federal Trade Commission, notes: “In most cases, using a higher-octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage or run cleaner.”
So is Higher Octane Fuel More Efficient? In a word, no. On its own paying for premium gasoline does not make your car run better or get greater gas mileage. Giving your car the fuel it requires to run smoothly and efficiently, without damage to the engine, does make a difference in your fuel mileage.
No, premium gas isn't a secret sauce for cleaning your engine. The main concern in engine maintenance is carbon build-up, which can happen over time with all fuel types if you skip routine checks. The good news is that both regular and premium gas have detergents that can reduce carbon deposits to an extent.
93 octane is likely too much for the Hemi and probably reduces the efficiency of the engine due to the difficulty of fuel detonation in the lower compression engine at the time of the peak power stroke.
It won't hurt the car at all to put a mix of 87/89 in, or straight 89, but your wallet may feel a bit lighter.
Should I put premium gas in my Ram 1500?
Most vehicles and trucks are designed to operate on regular fuel, though. So, filling your RAM 1500 or Jeep Grand Cherokee tank with premium is basically just throwing money away.
A HEMI® engine is composed of a hemispherical combustion chamber with dome shaped cylinders and matching piston tops. This creates less surface area than traditional engine which means that less heat and energy lost, and more power is produced.
The patented ProFlex™ Commander adaptive flex fuel system for RAM 5.7 HEMI V8-equipped trucks allows you to start making more power and running cooler with E85.
The available 5.7L HEMI® V8 engine with eTorque Mild Hybrid Technology System blends performance-enhancing and efficient technologies with the addition of an available extra 130 pound-feet of torque for a V8 gas towing capacity of up to 12,750 pounds( Disclosure1).
When it comes to the best overall octane booster, we love the Torco F500010TE Unleaded Fuel Accelerator. This octane booster can serve a wide range of engines and boost your car's octane levels as high as 102. It's also compatible with oxygens sensors and catalytic converters.
93 octane is likely too much for the Hemi and probably reduces the efficiency of the engine due to the difficulty of fuel detonation in the lower compression engine at the time of the peak power stroke.
It won't hurt the car at all to put a mix of 87/89 in, or straight 89, but your wallet may feel a bit lighter.
5.7L HEMI V8 Engine. Fuel Efficiency (4X2): 15 mpg city/22 mpg highway. Fuel Efficiency (4X4): 15 mpg city/21 mpg highway.
When it comes to the best overall octane booster, we love the Torco F500010TE Unleaded Fuel Accelerator. This octane booster can serve a wide range of engines and boost your car's octane levels as high as 102. It's also compatible with oxygens sensors and catalytic converters.