phatphil

Your always running more rpm's with 4.10's versus 3.55's it really doesn't effect gas mileage that much in 5th gear, but it sure is hard to keep your foot out of it in the lower gears, just alot of fun from stop light to stop light. Gas mileage definetly less in the city unless you do some serious gear skipping and grampa driving. Great gears for pulling on Vettes from stop light to stop light.

soldier boy

Ok i got u get the frpp 4.10's and it shouldnt make a big difference in fuel i am picking my car up in maryland and then driving it back to texas so i may wanna wait to get them in till i get there huh to save on gas its a 24 hour drive ....????

gidyup

I dropped -1 mpg with the 4.10s so (IMO) don't let gas prices affect your decision - you bought a Mustang, not a Prius right?

My shop said to give the gears ~200 miles of break-in before really romping on it so if you're planning to have a little fun on the trip home that might be one reason for waiting until you get to TX. Also, if you have any issues with the gears, dealing with a shop in MD would be a PITA...again, IMO.

...and as others have said: Thank you for your service to our country.

soldier boy

no problem but im gonna be in maryland and i still havent even driven my car so i still gotta go threw the intial break in maybe it will be good to break everything in at once ..... I been having my mom take my car around putting everything it has on it now so its all hooked up when i get home from iraq...

phatphil

When you getting out? If you come thru Missouri let me know and we'll compare cars.

soldier boy

Ill be home in late January.........

acascianelli

Which gears do you have now? 3.31 or 3.55? If you're coming from 3.31's, you might want to consider 3.73's if you think 4.10 might be too aggressive.

UDP's are a good mod, you won't notice a huge increase in power but there is a little. What I like most about them is that its a consistent power increase throughout the whole rev range. The small amount of low end torque I feel that I lost with my delete plates was completely negated by the pullies.

Norm Peterson

What you're waiting for during break-in of the rear gears is for the fluid temperature in easy normal running to drop. Gears of any ratio generate heat. Lots of it when they're first installed. You drive it easy for a few miles (I've seen 50 miles recommended, no racing, no highways) and see if the diff cover is hot to the touch. If it is hot, you're not done yet (IOW, rinse, repeat). Before a long trip like you've got planned, I'd rather see 500 miles or so on the gearset, as you won't be stopping to let them fully cool down every hundred or two miles (it can take overnight for a complete cooldown). More than 500 miles if you don't think you can suppress the urge to wind it out to see/feel the diffference that they make.

I'll also recommend an engine oil and filter change at a short first interval, in less than 800 - 1000 miles if that is still possible. Before your long trip, in any event. It probably won't be in the manual to do this extra service, but it can only help in the long run.


Thanksfor your service from an old guy who wishes you a safe return and plenty of good times in that '08.

soldier boy

yeah im gonna be home for a few weeks so i plant to get her broke in before i drive to texas ..I will also get the oil changed and all before i head home to texas.....You guys are very welcome and thanks for the info......