Best gear ratio for mpg?
05-23-2011, 11:33 PM
#21
Senior Member
Originally Posted by BassAckwards
Well if they didn't give the eco a taller gear than that seems like poor judegment to me on Ford's part. You got this motor that makes peak Torque at 1500RPMs and keeps 90% through the rest of the Power Band, and 1500-2000 RPM is right where you are at usually for highway speeds anyways so why not give it a taller gear?
I feel my 3.73 could use the extra gearing while empty for mileage, but it would hinder towing in 6th by causing more down shifting.
This would be more of a problem in 3.55 and more so in 3.15 etc.
I doubt Ford would make different transmission ratios for different rear axle ratios just to keep the drivability of some combinations acceptable.
I'm sure they tested many variations before settling on the best all round setup.
05-23-2011, 11:38 PM
#22
Originally Posted by dcfluid
All FX4 models, several times.
I did read testing of comparisons between the two and the transmission ratios were the same and comments were made as to the speculation that the ecoboost came with a higher 6th were wrong.
Now if I could only remember the article and discussions....
I did read testing of comparisons between the two and the transmission ratios were the same and comments were made as to the speculation that the ecoboost came with a higher 6th were wrong.
Now if I could only remember the article and discussions....
05-23-2011, 11:45 PM
#23
Senior Member
Originally Posted by borjeb
I was part of that discussion. The rpm I'm running corresponds directly to what 5.0 guys have. Using my edge insight which digitally tells rpm I am 1980 rpm at 80 mph (81 on dash, 80 digital). 3.31 gears
Correct me please on the peak torque of the ecoboost, I was wrong above and am searching the answer.
420 ft/lbs@(3000 ish?) rpm
Ok it's 2500 rpm! Brain fade...
Last edited by dcfluid; 05-23-2011 at 11:53 PM.
05-23-2011, 11:55 PM
#24
I Like Tires
Originally Posted by dcfluid
It makes peak torque I believe around 4000 rpm and makes up to 90% of that torque at 1700 rpm.
I feel my 3.73 could use the extra gearing while empty for mileage, but it would hinder towing in 6th by causing more down shifting.
This would be more of a problem in 3.55 and more so in 3.15 etc.
I doubt Ford would make different transmission ratios for different rear axle ratios just to keep the drivability of some combinations acceptable.
I'm sure they tested many variations before settling on the best all round setup.
05-24-2011, 12:07 AM
#25
Senior Member
Originally Posted by BassAckwards
True but on the same note you don't normally tow in 6th gear anyhow cuz the torque loss after 1:1 is ridiculous. It's an economy gear not a towing gear.
It's a credit the the manufacturers for making good power band engines matched well with excellent drivetrains.