More Info on R20

[Smith]

Hi,
Cal id is vxcf4h2 on 2006 F350. I tuned the truck to 100 hp and never seen a big improvement with mileage (very little). Fairly good power from a roll, poor from a stop. Started the truck at zero degrees fahrenheit and the truck barely ran, coughing and sputtering for a couple of minutes then finally smoothed out. Tuned truck to 65 hp and it started a lot better and improved the mileage maybe 1 mpg. Very poor power with 65 hp from stop but once the turbo spools, it seems to have fairly good power. I always seem to get the best mpg with 100 hp but not with this tune (R20). The problem with starting is not good. Any ideas?

DS

[Smith]

Can anyone answer this question?

DS

[jr7975]

Im new to the forum but im on my 4th superduty truck. I currently have an 06 with the R20 tune and have the same Problem You do. The sputtering is due to the direct injection module not being able to compensate for the new tune. I started my truck in Sub- zero weather and noticed that switching to synthetic oil helped dramatically. The hard run doesnt hurt the truck(so im told by a local diesel performance shop). Ive gotton best MPG on the 100hp tune with my hubs unlocked- 18.6 locked-14.3. I have a K and N CAI accufab elbow and 5" turbo back no cat. hope this helps!

[Smith]

Thanks jr7975 for the info. I thought for a moment that no moderator could read in this forum. Just wondering why no moderator could answer this question?

DS