New Diesel Postponed So Help With Mpg

[droptail]

I have been waiting for the new LD 4.5L diesel to come out, but of coarse that isn't happening now. Can't even get a RC Hybred, so...

 

Is there a thread (I didn't find in a search here) that address's improving mileage for my (little) 1990 (see mods in sig)? I get 16 mpg combined with very light acceleration & short/skip shifting, which seems typical to good here. Just wondering if there is something I missed.

 

On another note, would increasing rocker ratio and going to roller necessarily hurt mileage if I stay out of it? I miss the pull of my Edlebrock cam kit on my (RV cam) rebuild.

 

I will swap back my Holley using the vacuum port mod/info and retest for mileage.

 

Thanks

[kuhl_530]

A K&N air filter, new fuel filter, replace plugs, wires cap&rotor (if applicable) would be a good start. You can also try switching to all synthetic fluids in your engine, trans, and gears. To be perfectly honest, though, I've only heard of gains of approximately 1-2 mpg by switching to synthetics, and maybe 1-2 by switching to a k&n. I put a k&n cold air intake, msd blaster ignition coil, 8.5mm wires, msd cap&rotor, double platinum plugs, and a flowmaster exhaust kit, and all together I think I gained about 1 mpg mixed city and highway milage.

 

The fact of the matter is, you can squeeze only so much out of a vehicle before you're just pissing money away.

 

From experience, the best way to save on gas in a pickup is keep it light, keep the tires inflated, keep your foot off the gas, and coast coast... coast!!! lol

[OldCrLvr]

As far as the rocker arm question goes. By upgrading to roller tipped or full roller (depending on budget) you are reducing friction thus freeing up horsepower. Theoretically you would be gaining mileage. There is a nice article about roller rockers I found on the Car Crap web site. On average full roller rockers free up 8-10HP. Car Crap found they got 11HP and 6FtLb's of torque. Here is the link: http://www.carcraft.com/techarticles/116_0101_roller_rocker_ratio_test/index.html

 

Some guys do the split ratio rockers to get some more performance. It is actually a real popular thing to do. This is where you would put 1.5's on the intake and 1.6's on the exhaust. Here is Summit's explanation: "The lobe lift of the camshaft is increased by the ratio of the rocker arm to produce the final amount of valve lift. A cam with a .320” lobe lift using a 1.5 ratio rocker arm will have a .480” valve lift (.320” x 1.50 = .480”). If you install 1.6 ratio rocker arms, final lift will increase to .512” (.320” x 1.60 = .512”). The engine will respond as if a slightly larger lift cam had been installed. Increasing the rocker arm ratio is an easy way to improve the performance of an existing cam."

 

The prices of SBC valve train parts have been coming down in the last 10 years. I checked with Summit and you can get a set of Proform 1.5 ratio roller tipped rockers for $75 and a set of full roller's for $186. I personally run Harland Sharp's full rollers and they are I think around $220. If it was me I would get a set of full roller 1.5 ratio rockers.