SCT tuning - performance and extreme

[bsudkamp]

I tested both the performance tune and extreme tunes using the race transmission settings. I noticed that EGT's and boost were much lower running the extreme tune at both 65 and 70 mph. I have to believe this is good and should mean better mpg's. Is this assumption correct? What are the downsides of running the extreme tune?

[Matt@SCT]

The Extreme Tune is were everybody have been seeing the best Fuel Economy when they are keeping the vehicle around 2000 RPMs. I have not seen any problems running on the extreme tune.

[bsudkamp]

Thanks. I'll keep running the Extreme Tune. Will the cat hurt fuel economy?

[Matt@SCT]

On our 6.4 we just installed the DPF delete and we didn't run into any problems with the Cat.

[bsudkamp]

Thanks. I'll leave the cat on for now.

[Matt@SCT]

No Problem

[Abrannan19]

you will see better fuel mileage with removing the cat too, its a big source of restriction.

[twinturbostroker08]

im running my truck on extreme with the cat/dpf delete pipe installed, so far im satisfied, i hope to get an RCD tune pretty soon, ive had my tranny slip once though..and sometimes it kind of jumps from first to second gear

[bsudkamp]

What's the RCD tune? Who provides the tune? What are the benefits?

[SANDSAILOR]

Originally Posted by bsudkamp

What's the RCD tune? Who provides the tune? What are the benefits?

RCD = River City Diesel, there on here and you can go to there website rivercitydiesel.com. The benefits are better mpg and oh sht I think I just craped my self speed. The 585 is crazy fast but I highly recomend trans upgrades as its pushing very very close to 600 rwhp and will over power a stock trans over time. The 485 is one sweet @$$ street tune that will dust most every thing on 4 wheels on the street.