I bought an 06 silverado approx 5 wks agowith RODABURNERS on it,carb
jetted but not over done/too fat on fuel calibration as many shops do which is key.
But the prior owner had the car setup too rich,i could litterally pump the gas 2-3 times for a little prime and fire it up dead cold/50-55 deg F with no choke at all and could take right off 20 seconds later after letting the motor get some oil pressure going,thats too rich IMHYO.
So i backed off on the fuel calibration a tad so i now have to use a littl choke to get it fired up and & keep it running for 1-2 mins ,then after that i can pull away feather clutch/gas a bit and take right off with no heasitation/or sputtering/backfiring thur carb nada,and it will idle ok then too,much better that way and plugs look better too.
Run great now when hot,motor seems a little crisper when it coms to throttle resonce esp comming off idle now that it's not setup over rich which made it soggy esp when it was hot.
So post that carb tweak I have tested 3-4 tanks of fuel for mileage all of it being mixed type driving with a little in stop go traffic but majority in rural areas/out in the country sort of speak anywhere from 40-60mph with plenty of stops here and there as for people turing off main
roads i was on to homes or smaller side roads.
Anyway,best was 45mpg in that mixed driving being very very good short shifiting it and not heavy handing the throtle either. That's because every little touch on the throttle on these bikes gives a shot of fuel into carb from accell pump which can kill fuel mileageesp if your the type that's on & off the gas all the time.
So on the open raod/interstate at maybe a steady 65-70mph i think should be able to get at least 47-48mpg and maybe even 49-50pmg with the wind behnd me.
But on avg i got 37-38mpg in that mixed driving without wife on back.
A friend of mine cant break 35mpg with his 05 R* with cobra pipes & jetted carb with only him on it,it kills him when he see's me getting 50+ mpg on my other bike riding 2 up when we ride together with only him on his bike & 2 people on my bike with windscreen & bags on that bike too.
My other bike riding 2 up /wife and myself consistantly gets 50-51mpg in that same mixed driving stated above. My other bike is a 1977 kawi kz1000 4 cyl inline & 4 26mm carbs with 4 into 1 kerker. But the R* cant touch that mpg riding 2 up in that mixed driving,thats for sure. Of course i fine tuned/dialed in the carbs for the 4 into 1 kerker pipe for a little additonal fuel it needs with the better breathing kerkr but not to rich /fat which many people do and thats why i get such good mileage with that bike. Been rididng that bike in that state of tune 33 yrs since i bought it new in 77 and emidiately installed the kerker and tweaked the carbs.