milage 6.2 chev van g20 diesel Submitted by an Anonymous Greaser on Wed, 2010-01-13 02:49 curious.on the mileage of a van in good condition of its highway mileage. Reply to this post I've got a '90 GMC Suburban Submitted by an Anonymous Greaser on Sat, 2010-01-16 01:13 I've got a '90 GMC Suburban that I run a single tank system on, and I get about 20-23 mpg, whether it's using diesel, wvo or mixed. I don't know what the weight specs are, but unless yours is a conversion van, and maybe even if it is, I'd think they may be close. Mine is automatic, 2wd with a 700 tranny. All the seats are in. I guess you would have to deduct some weight for the rust holes in the rear quarter panels and bracing under the back door. :) reply Reply to this post Your name Comment * Location * What code is in the image? * Enter the characters shown in the image.