LSI Posted September 17, 2011 Share Posted September 17, 2011 (edited) Can't make up my mind weather to go with a SCR 2011 or stay with a low mile 2009 or 10 with only DPF.The 2011 with less EGR and with SCR get better fuel mileage and are reported to have less problems.I'm working on gearing now.I run 62 to 65 with 80000lbs.I run Mo,Il, and Wi.I have a 13 spd and 3:58 rears,with 515hp ISX.It might be the ISX cause its a little short on power from 40mph to 60mph.From 25mph to 35mph at 1500rpm it pulls like a dog on fire.If this was an older truck it would tell me to go with 3:70 rears,moving the power to mid range on speed..Whats your take? Edited September 17, 2011 by LSI Quote Link to comment Share on other sites More sharing options...
james j neiweem Posted September 17, 2011 Share Posted September 17, 2011 2011 higher initial cost but it has a warrantee, probably less headaches, better mileage, higher resale and you can spec the tranny & rears to the torque and HP curves. Veryvery important as you know gearing gearing gearing. The old 170hpB-61 dumps could keep up with 220HP Acar and IH dumps because of gearing gearing gearing. Remember If it is not speced right it will never be right. Ideally a test drive loaded would be in order. Good luck. Quote Link to comment Share on other sites More sharing options...
farmer52 Posted September 17, 2011 Share Posted September 17, 2011 Reviews of the 2011 engines with SCR are better than the pre-SCR engines. Quote Ken PRR Country and Charter member of the "Mack Pack" Link to comment Share on other sites More sharing options...
Underdog Posted September 18, 2011 Share Posted September 18, 2011 At 62 to 65 MPH you may want 3.70 or even 3.90 axles to keep the RPM's happy in high gear. Another option is to spec faster axles (3.58 or 3.36) and a direct transmission for better fuel economy. I agree with Ken the SCR trucks are less trouble than older EGR trucks and you can spec the gears you want if you order brand new.Gregg Quote Link to comment Share on other sites More sharing options...
Mackpro Posted September 20, 2011 Share Posted September 20, 2011 Can't make up my mind weather to go with a SCR 2011 or stay with a low mile 2009 or 10 with only DPF.The 2011 with less EGR and with SCR get better fuel mileage and are reported to have less problems.I'm working on gearing now.I run 62 to 65 with 80000lbs.I run Mo,Il, and Wi.I have a 13 spd and 3:58 rears,with 515hp ISX.It might be the ISX cause its a little short on power from 40mph to 60mph.From 25mph to 35mph at 1500rpm it pulls like a dog on fire.If this was an older truck it would tell me to go with 3:70 rears,moving the power to mid range on speed..Whats your take?We have sold alot of 2011-12's and no problems with the SCR/DPF or engine(except of loose battery/starter cables on every one?) . MPG is great as well as power. Mack and Volvo are beating everybody on MPG when spec'ed correctly and road speed is kept to a reasonable level. The MP engines are much more foregiving when the tire size/rear gear ratio and transmission dont quite match up. Any good salesman can tell you what gears you need to match your tire size and desired cruising speed. When our salesman is ordering a new truck, if he enters a gear ratio or tire size that dont quite go together, it throws up all kinds of red flags and warns the salesman. I've seen him do it! 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.