85 300SD rear end ratio

I want to maximize my diesel economy. Is the rear end ratio in a, say, 560 SEL of that vintage interchangeable with the rear end on my 85 300SD ? What are the two respective rear end ratios? Thanks so much!
Tom

Forums

Transmission / Suspension Specific Aid

Chassis Model Number

W126

the "ol mark and turn

if you have access to both cars jack up the rear trans in nutral mark the tire and the wheel well tape works turn the tire one revolotion count how many times the driveshaft spins (2.x times you got a 2.06 ect.) for better fuel milage good tires,injector balance and upgrade, diesel purge,filter change and a K+N air filter you'll be good to go! any one of these will gain you something. swaping the rear ends for a higher gear (numarically lower) i would (and have) done the listed things and it's just better all around for the car. I wish i could get about a 3.something gear insead of the 2 gear it came with but mercedes knows more than i do about staying in the powerband of the diesel engine they ENGINEERED! I think going higher will take you out of the powerband and you will not see as much or any differance. Go with the things I listed all that good stuff is sold on this site.