It diminishes the accelration in 3 ways:
1) It changes the gearing of the truck
2) Larger wheels are usually heavier (except for certain light weight wheels) so it adds overall weight to the truck
3) Large wheels also create more rotating mass, meaning the engine has to work harder to get them turning
main thing is you need to measure the overall tire height of yours and the new ones. The tires on the 20's are a lower profile so I am sure that the overall isn't going to be that much different in the end.
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'98 Ram Sport 5.9 4x4 -Gas guzzling plow truck
'05 Cobalt 5 Speed - Lease, everyday beater when its not in the shop, shoulda got a Dodge...
It diminishes the accelration in 3 ways:
1) It changes the gearing of the truck
2) Larger wheels are usually heavier (except for certain light weight wheels) so it adds overall weight to the truck
3) Large wheels also create more rotating mass, meaning the engine has to work harder to get them turning
Ok, so
1) So I need more reving for the same speed?? what does the 3.92 axle does?
2) I have the polished alluminium wheels (stock 20s), how much more heavy are those than the average 17" (also stock)
3) So, it really can make a difference or it I couldnt tell the difference if I get the 17s.?
It diminishes the accelration in 3 ways:
1) It changes the gearing of the truck
2) Larger wheels are usually heavier (except for certain light weight wheels) so it adds overall weight to the truck
3) Large wheels also create more rotating mass, meaning the engine has to work harder to get them turning
Ok, so
1) So I need more reving for the same speed?? what does the 3.92 axle does?
2) I have the polished alluminium wheels (stock 20s), how much more heavy are those than the average 17" (also stock)
3) So, it really can make a difference or it I couldnt tell the difference if I get the 17s.?
1) If one truck had a lower profile wheel/tire combo, but they both had the same gears, the the truck with the lower profile combo would require more RPM's to maintain the same speed as the other truck. The 3.92 gears means that for each revolution of your driveshat, your wheels are turning 3.92 times that.
2) I'm not sure on the weight of either wheel, as I have the 20's with the chrome wheel covers.
3) There will be a slight difference, but overall it won't matter too much.
Also, about the gearing, it will depend on the overall height of both sets of wheel/tires. If you know the tire size used ont he 17's you can use this calulator to find the difference on overall height.
The 3.92 gears means that for each revolution of your driveshat, your wheels are turning 3.92 times that.
You have it backwards. The driveshaft has to make 3.92 revolutions to make the tire spin once.
__________________
'98 Ram Sport 5.9 4x4 -Gas guzzling plow truck
'05 Cobalt 5 Speed - Lease, everyday beater when its not in the shop, shoulda got a Dodge...
If anyone has a bare stock 20" rim they can weigh, I have a stock 17" from an 04 Ram. From the 04 Ram shop manual;
265/70/17 661 revs /mi.
275/70/17 649 revs
275/55/20 655 revs
275/60/20 636 revs
So it looks like the 17's have a smaller diameter, in general, than any of the 20's. That combined with the lower weigh of the overall tire and wheels combo.....
20 Wheels
