My 85 bronco with a 351w, c6, and lsd 3.55s will bust 34s loose. Why do people complain about 3.55s with 33s?
I have a healthy 300 in front of a 4spd manual. 37s and 4.56s and get about 12 mpg.I currently have 3.55s with 35s and I could notice the difference between 3.55s with 33s and going to the 35s. My engine is pretty well built and can still break the 35s loose easily but I still lost acceleration with bigger tires and plan to swap to 4.56s in the future. My current fuel mileage is about 10 mixed driving and 13 highway at 65 mph.
Makes sense you got better mileage wI have a healthy 300 in front of a 4spd manual. 37s and 4.56s and get about 12 mpg.
With my 94 With a healthy 351w , I got better milage with 4.88s and 37s than 3.55s and 37s or 35s. Again, about 12 mpg.
The main reason for increased milage is a tremendous change in throttle input. With the throttle barely open, it uses much less fuel. 50% throttle at 2200 is probably gonna suck more fuel than 20% at 3000 rpms. This is very relevant to the six cylinder crowd for good economy.Makes sense you got better mileage w
ith lower gears. Engine is working less at lower speeds. Must override the higher rpm at highway speeds. My mpg for just city driving is generally pretty bad, 8 or so usually. I bet 4.56s would help alot, I have to give some throttle especially on hills to get the heavy 35s i have moving. I have a 4 speed manual as well.
I also destroyed my driveshaft a few months ago. Probably has something to do with the 3.55s, 35s and hopped up 347...
sounds like you have alot of converter slippage or something wrong.. using chart above, 35 and 4.56 would be 2847 at 65mph. divide that by 65 and multiply it by 75 and its 3285. if its a C6 without lockup converter, add a couple hundred rpm but should not be adding 600rpm89 5.8 C6 35s 4.56 gears. Whatever you do, avoid any situation where any speed over 65 is needed. Speed limit on the highways is 75 here, and my truck pushes 3,800 rpms at that speed. Garmin GPS for speed accuracy, using factory in dash tachymeter.