Silverado 5.3 vs. F150 2.7L
10-20-2015, 02:19 AM
#71
Senior Member
10-22-2015, 10:31 PM
#73
Senior Member
I've driven F150s for years. But I travel and rent cars every week and have driven several Chevys with the 5.3 and it felt a bit sluggish compared to all the Fords. I was impressed with highway mpgs of over 20, but the city was around 15. The Silverado, Tahoe and Suburban would get over 20 mpg highway. My 2.7 gets 18 city and 20 highway with 3.73 gears. You could improve upon that with higher gearing.
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Mikemeek (10-22-2015)
10-23-2015, 07:58 PM
#74
Senior Member
More gears won't necessarily mean that many more mpg's. If 10th gear is the same final gear ratio as the present 6 speed, your highway miles won't increase much. A higher final ratio might probably mean you will rarely get to 10th unless you go faster (less mpg, more wind resistance?).
If you do a lot of stop and go it will help with the low end and increase mpg, but if the parasitic loss in the transmission is not lower than the present 6 it won't be a whole lot more.
Rams ZF 8 speed had a little over 20% less parasitic loss over the 5/6 speed RFE with the same final ratio and it was this mostly and with a little help of the extra gears that increased the Hemi to 23 mpg. 2 to 3 mpg increase over the RFE.
Will be interesting to see how this works out.
If you do a lot of stop and go it will help with the low end and increase mpg, but if the parasitic loss in the transmission is not lower than the present 6 it won't be a whole lot more.
Rams ZF 8 speed had a little over 20% less parasitic loss over the 5/6 speed RFE with the same final ratio and it was this mostly and with a little help of the extra gears that increased the Hemi to 23 mpg. 2 to 3 mpg increase over the RFE.
Will be interesting to see how this works out.
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Mikemeek (10-23-2015)
10-23-2015, 09:35 PM
#75
My real world 2.7 mpg is not that great. Computer read 15.5 on first tank. Will do pencil and paper on second tank, but computer is reading 16.8 currently. Daily trip to work consists of 12 miles at 70mph, 4 miles at 55, and 1 mile at 45.
10-23-2015, 09:52 PM
#76
Senior Member
More gears won't necessarily mean that many more mpg's. If 10th gear is the same final gear ratio as the present 6 speed, your highway miles won't increase much. A higher final ratio might probably mean you will rarely get to 10th unless you go faster (less mpg, more wind resistance?).
If you do a lot of stop and go it will help with the low end and increase mpg, but if the parasitic loss in the transmission is not lower than the present 6 it won't be a whole lot more.
Rams ZF 8 speed had a little over 20% less parasitic loss over the 5/6 speed RFE with the same final ratio and it was this mostly and with a little help of the extra gears that increased the Hemi to 23 mpg. 2 to 3 mpg increase over the RFE.
Will be interesting to see how this works out.
If you do a lot of stop and go it will help with the low end and increase mpg, but if the parasitic loss in the transmission is not lower than the present 6 it won't be a whole lot more.
Rams ZF 8 speed had a little over 20% less parasitic loss over the 5/6 speed RFE with the same final ratio and it was this mostly and with a little help of the extra gears that increased the Hemi to 23 mpg. 2 to 3 mpg increase over the RFE.
Will be interesting to see how this works out.
10-23-2015, 10:59 PM
#77
Wish the rest would do what Ford did. Breakdown epa ratings in to payload class, but rear ratios would be nice too.
Last edited by canoepaddler; 10-23-2015 at 11:09 PM.
10-24-2015, 04:23 AM
#78
Senior Member
10-24-2015, 05:14 AM
#79
Senior Member
ok with 8 gears in the dodge dose that mean its got 4 over drive gears now?
and dose it hunt even harder to find a gear on a hill or in a head wind?
what about towing dose a truck passing you make it shift down 3 gears?
and dose it hunt even harder to find a gear on a hill or in a head wind?
what about towing dose a truck passing you make it shift down 3 gears?
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canddmeyer (10-24-2015)
10-24-2015, 09:01 AM
#80
GM must be doing it wrong because Ram gained 2 MPGs with their 8 speed. http://www.fueleconomy.gov/feg/Find....35744&id=35747