Xoutpost.com - View Single Post - What did you do to / for your E53 today??

workingonit · #**16411** 01-06-2024, 03:19 PM

Quote:

Originally Posted by Salty B.

...My non-sport X5 is a fine cruiser. It's got the basic 17" wheels which means tall tires and soft(er) ride. Sure could use an overdrive tho...

Quote:

Originally Posted by Bdc101

...Same here, I have the 17" wheels as well and it's a wonderfully comfortable cruiser - but man I like to keep the speeds low. Not just for MPG but also because it revs SO high! I took a couple road trips to Idaho last fall, where they have 80mph speed limits on the interstate, and everybody goes 90.

My '01 X5 has 17's also, and cruises just great at 75-80 mph. The automatic 5L40E tranny has a .75:1 ratio in fifth gear, that really helps lower the rpms that the 4.11 final drive causes. It has been my favorite highway cruiser from the last few decades; only my '67 Dodge Monaco 500 (383 magnum V-8, 3.23 rear gear ratio) cruised better, but then, my memories of it are 50+ years-old). My wife's '14 Lexus ES350 is a smoother, softer, more fuel-efficient cruiser, but it isn't an X5 !!

Using this rpm calculator https://www.crawlpedia.com/rpm_gear_calculator.htm, it shows my 3.0i is at 2679 rpm @75 mph (compare that to the 2547 rpms that my '04 Chevy 2500HD gets, with a taller 30.5" tire and same final drive ratios). The BMW 3.0i uses less gas than the 6.0l LS V-8 that the pickup has, though (15-20 mpg for the BMW 3.0i vs 13-15 mpg "max" for the Chevy 6.0l).

I can live with that, since I formerly drove my old '66 Chevelle (before I converted it to full-race), and my '69 C-10 daily driver/tow vehicle, with 3.73 rear gears and no overdrive gearing in the transmission(s) (both had TH350 trannys at the time). Very poor fuel mileage, but theywere fun.

The Chevelle had a 427 c.i engine, a 800 cfm Holley double-pumper carb, and 28" tires (450+ whp, 7-10? mpg, 3357 rpm@ 75mph), and
the C-10 had a 355 c.i. engine, a 750 cfm Holley street carb, and 31" tires (380 whp, 11-13? mpg, 3032 rpm@75 mph)

You should've seen the highway rpms when I switched to 4.56 rear gears on the Chevelle, just as I was switching it to full-race status (4104 rpm @75 mph).

In its' final configuration, it had a different engine, with 14:1 compression, 441 c.i. (solid-roller-cammed), a 1053 cfm Holley 4150 double-pumper carb or a 1200 cfm Holley Dominator 4500 carb (depending on whether I was racing 1/8th mile or 1/4 mile tracks, and cool or hot weather...different intakes and tune-ups were used, also). (4392 rpm @75 mph) Very low mpg on expensive 118 octane fuel !!

Sponsored Links

Sponsored Links