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2021 Fuel Economy, am I lower than expected?

JE_75PW said:
Well, I hit 7.5 MPG.
- Running 87 octane
- 35 Toyo's
- city driving ( small city - 6-8 traffic light on commute to work, approx. 12-15 miles)
- truck only - not towing - empty box
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Ouch!!!!!
 
@JC said:
Almost 1100 miles in 2 days, pulled an empty open trailer (about 900 empty) 1 way and loaded the other way (1700 loaded). Wind was mostly from the side with a 50/50 mix of 78 on the Interstate and 68 on the regular highways. Net hand calculated average over the whole round trip was 12.4mpg. I was actually pleasantly surprised it was so high.
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Hmmmm …. Just got our 2020 2500 Hemi and pulling nothing on long highway stretches to/from our land we’re getting a sorry 8-10 mpg. Gotta educate ourselves quickly on what we need to improve ….. find myself driving my old 03 gas Silverado beader’
 
JE_75PW said:
Well, I hit 7.5 MPG.
- Running 87 octane
- 35 Toyo's
- city driving ( small city - 6-8 traffic light on commute to work, approx. 12-15 miles)
- truck only - not towing - empty box
Click to expand...

People dont realize the penalty of larger (heavier) tires and running gear. 7.5 seems oddly low, but there is definitely a price to pay for a nice set of shoes.
 
Ouch. I totally missed the 87 octane part.

nope.. not in my vehicles lol!!
 
gimmie11s said:
People dont realize the penalty of larger (heavier) tires and running gear. 7.5 seems oddly low, but there is definitely a price to pay for a nice set of shoes.
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100% on that one.
I did not realize the penalty would be this high. I knew the 35's were around 22lbs heavier, I really thought it wouldn't be noticeable. I never consider rotating mass at all.

If this is the price to pay for tires than, it is what it is. I'll take it.

I'll switch to 89 for a couple tanks and monitor. i'll also track the actual number just to verify the truck calculation ( but im sure it good)

Its interesting, 89 is recommended for the 5.7, however 87 is recommended for the 6.4

I appreciate the feedback on this one
 
Wow. I get 87 all the time. Most places it a choice between 87 or 93 and I'm not ponying up to pay for 93.
 
my 202 owners manual says 87....
FUEL REQUIREMENTS — GAS ENGINE
6.4L ENGINE
Do not use E-85 flex fuel or ethanol blends greater
than 15% in this engine.
This engine is designed to meet all emissions regulations and provide satisfactory fuel economy and performance when using high quality
unleaded gasoline having a posted octane number range of 87 as specified by the (R+M)/2 method.
While operating on gasoline with an octane number of 87, hearing a light knocking sound from the engine is not a cause for concern. However, if the engine is heard making a heavy knocking sound, see dealer immediately. Use of gasoline with an octane number lower than 87 can cause engine failure and may void or not be covered by the New Vehicle Limited Warranty.

I run it and get great mpg with 35's..
7CAAEC7B-3FE3-4557-AAC0-0BC45BAB231E.jpeg
 
jadmt said:
my 202 owners manual says 87....
FUEL REQUIREMENTS — GAS ENGINE
6.4L ENGINE
Do not use E-85 flex fuel or ethanol blends greater
than 15% in this engine.
This engine is designed to meet all emissions regulations and provide satisfactory fuel economy and performance when using high quality
unleaded gasoline having a posted octane number range of 87 as specified by the (R+M)/2 method.
While operating on gasoline with an octane number of 87, hearing a light knocking sound from the engine is not a cause for concern. However, if the engine is heard making a heavy knocking sound, see dealer immediately. Use of gasoline with an octane number lower than 87 can cause engine failure and may void or not be covered by the New Vehicle Limited Warranty.

I run it and get great mpg with 35's..
View attachment 26899
Click to expand...

gimmie11s said:
Cant believe they put that in the owners manual... What in the............. lol
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Haha.

Where are all those Hemi tick or noisy Hemi complainers at? Tell them “it’s not a cause for concern” lol
 
2022 manual says 87 as well.
just finished a 1300mi trip, averaged 12.5mpg on the gauges, no towing and about 500lb in payload
i ran 87-89 octane, i was never really trying for the best fuel economy but wasn't racing it either, just driving
a lot of elevation changes on the trip where i saw the mpg take some large hits but overall it is right where i expected it to be.
If i cruise around at 45-55 i get about 15-16mpg with eco on
 
I always run 91 but that's because that's the only way to get non-ethanol around here. I refuse to put corn byproduct in any of my vehicles or small engines.
 
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