Q: gas mileage difference 383 stroker motor 400 hp or ls3 computeried 400 hp same car

asked by on

I am wanting to get more power from my car but gas mileage is important.The gas mileage difference between the 2 engine choices mentioned

My car has 57000 miles.
My car has a manual transmission.

The gas mileage attained in either of these applications will depend heavily on your driving habits as you may already know. Either of these will also depend heavily on the type of intake system you are using to arrive at your 400 hp number.

When you say 383 stroker motor, I would assume you are speaking of an earlier generation 350 Chevrolet with the 400 c.i. crank and rods arriving at the 383 CI. Also, are we assuming both of these options would have the same intake manifold and fuel injection? As you may know this will also have a large impact on the type of camshaft, ignition timing, valves, etc. which will all affect fuel economy.

Since there are a lot of factors at play that determine horsepower and gas mileage numbers, it is very difficult to project which will do better in terms of fuel economy. However, the convenience and automatic adjustments that a computerized fuel injected motor offers are going to be much more accurate than a carbureted motor of the same horsepower.

Without knowing more detail, I would say from a big picture standpoint, the LS3 motor will do much better on fuel.

If you’d like a second opinion on this, have the car inspected by a certified technician, such as one from YourMechanic.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. gas mileage difference 383 stroker motor 400 hp or ls3 computeried 400 hp same car

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: How do I get my car's miles to show on the dash while the car is on?

Your car has a multi function display that can show mileage, trip mileage, service intervals, and other information. It sound like you may be having difficulty getting it to display what you want. Your car will either have buttons on...

Q: The coolant hose between the radiator and engine is kinked. I think its either the thermostat or the water pump. Please advise how

You will need to replace the kinked hose to restore flow to the engine. This is the bypass hose so coolant flows through the engine before thermostat opens.

Q: Motor and transmission compatability

Hi there, thanks for writing in. The GM 4.3l V6 was also an engine choice for 2nd generation S-10s (1994-2004), so parts and information on a conversion to that drivetrain are plentiful and affordable (as swaps go). Check out the...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.