Originally Posted by Gus Riley
Details, details. When I set the cruise for 84 mph (because our Jetta speedometer runs about 3-4 miles fast) and leave it at that speed for hours, I think it's pretty safe to say our avg is close to 80 mph.
TDi.
Well... if you drive at 80mph with no slowing down at all for 8 hours, and spend 2 hours at a 40mph average speed, or some approximation of that, you'll only be at ~72mph. In any event, from everyone I've read, TDIs follow the 120-speed=~mpg rule. Meaning 120-70=~50mpg, or 120-80=40mpg. I'm guessing your trip average was ~75-77mph.
If you can stand to keep the cruise at 55mph, you should get into the
high sixities. Or at 25mph in top gear,
~100mpg. So, if by not much better, you mean an extra ~20+mpg, then sure.
Wrt to what Gus Riley said, it works for me in semi busy traffic, since having everyone pass me means I can just sit back and only worry about what's in front of me as opposed to having to deal/change my speed because of those around me. Otoh, if I were in an area where I could go 70mph non-stop w/ no hassles, then I could probably go farther. YMMV.