Can you put regular gas in a 5.7 Hemi?
Regular is OK. Mid grade is recommended. Premium is a waste of money. This assumes it is a Hemi.
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. Gasoline with this octane number is good for engines with compression ratios of 9:1 to 10:1.
If the octane rating is less than 91, you could damage the engine and may void your vehicle warranty.
What kind of gas does a Dodge Ram 1500 take? A Dodge Ram 1500 uses regular gas. But Ram recommends an 89 octane for the V8 engine, which is a mid-grade gas. However, the V8 will also run on regular gas as well.
Changing to a higher-quality fuel and higher-quality oil may also help. Using high-quality synthetic oils is one way people avoid developing the Hemi tick. Of course, if there is a concern that debris is trapped in the engine, an engine flush may do the trick.
You can mix 87 and 89 gas. However, it's a bad idea because the two fuels have different octane ratings. When you put them together in your car's tank, the engine will try to adjust to the lower octane rating of 87 and could potentially cause damage.
Honestly, using a higher octane gasoline than what is intended for your vehicle offers absolutely no benefit – your car will not run better, go faster, run cleaner or get better gas mileage if you use a higher than required octane level.
Regular gas is rated at 87 octane in most states, while premium gas is often rated higher at 91 or 93. Fuel with a higher octane rating can stand up to higher compression before it detonates. Essentially, the higher the octane rating, the lower the likelihood that detonation happens at the wrong time.
Premium unleaded' runs 91 octane and is, generally, only required for 'maximum performance' by performance cars. Using premium unleaded in those vehicles will, generally, give you the best miles per gallon and peak performance from your engine.
However, remember this: when a premium fuel engine runs on regular fuel, there's a risk of combustion of the fuel mix before the spark plug even lights up. This causes a phenomenon called knocking, which is likely to damage the engine.
What happens if you put regular gas in a V-8?
If you mistakenly fill up with regular fuel, your car's ECU will adjust engine timing and performance to work with the lower-octane fuel. In most cases, this is ok for the times when there are no premium pumps around, but it's not ideal to run the cheapest fuel possible for extended periods of time.
Fuel with an 87 octane rating burns more quickly while higher-octane fuels burn more slowly. In engines designed for standard unleaded fuel, efficiency and performance is optimized for 87 octane and could actually perform worse with higher-octane fuel since the burn rate is slower.
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.
The compression level of the engine in a hot wet climate likely dictates 89 octane for the best engine efficiency. 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.