Heavy Weight Flywheel?

[BuildingToys]

I am putting together a new motor and tranny combo and am looking for any one who has tried or has input on using a heaver than stock flywheel. Pros and Cons!

[grandeyota]

I know people that swear by them but I keep thinking MPG will go down.

[Rocktoy2]

Mine made a big difference in drivability. It helps off road when you're at idle. I don't think it makes a big difference on the rocks. Perhaps with crawler gears it might. I haven't noticed a change in fuel mileage. Your drag racing days will be over but it makes it easier to bark the tires. I can't really think of anything negative.

[BigMike]

Actually gas mileage should improve on flat freeways, but not in the city.

The flywheel will give so much inertia that it will require less energy to maintain your speed. But if you are doing a lot of passing and accelerating, then that's what's gonna get ya.

When I put in a 11 lb flywheel in my MR2, replacing my 20 lb stock flywheel, I lost around 5 mpg, seriously.

[TOYJOETA]

I have one in my truck couldn't really tell the difference.  I does climb small ledges alot better though, no real diff on the road.

[BuildingToys]

Thank You All! That is all good info but I do have one more question. I am running 4.7:1 Crawler Gears and 4.37 diffs.My concern is there may be a time when I may be bound up in some rocks or the likes. Will the extra weight of the flywheel cause other pre-mature failures in the drivetrain.

[kyle_22r]

i really wouldn't think a heavier flywheel would cause any more failures than a stock one.