V-10 question

Sorry, I can't put an actual number on it, but the difference might be pretty great. I've got 4.30 gears in my V-10 F-250 and cruising at

70-75 mph drops my mileage quite a bit. Off the top of my head, I don't know what my rpm is at 75 vs 55, but I know I see about a 2-3 mpg difference between the two. (Of course aerodynamics plays a part too......)

Matt

99 V-10 Super Duty, Super Cab 4x4
Reply to
Matt Mead
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I have an RV with the V -10 Triton engine.The tranmission is a Ford automatic 4 speed. I think the ratio is 5:38 ? or something like that. I have a question about mpg atg certain rpms. I haven't been able to calculate my mpg because we use the generator a lot and it uses the same gas tank. Here's my question: what is an efficient cruising rpm? I'd like to cruise at 60 mph but I can't do it at 2500 rpm.2500 rpm is about

57-58 mph. Does anyone know the difference in mpg between 2500 rpm and 3000 rpm?

Tim, Looking to expand Seniors (55 + ) Daytime Pool League

Reply to
Tim Dolan

The difference in Gear Ratios don't relate as the Motor Home has 19' wheels.

Reply to
Mellowed

bullshit

it could have 24" ( " = inch, not ' = feet) wheels, and the gear ratio would still enter into the equation..........

Reply to
Gary Glaenzer

Clearly you have got your head up your ass. The gentleman that I was responding to was comparing his 4.3 gear to the motor home 5.38 gears. This comparison is invalid since the Motor Home has 19" wheels. It would compare if and only if the Motor Home had 16" wheels.

: > The difference in Gear Ratios don't relate as the Motor Home has 19' : wheels. : >

: >

: >

: :

Reply to
Mellowed

well, learn to include the ENTIRE discussion that you're referring to, not just one paragraph with a one-sentence reply that makes you look like a goddam idiot, then

Reply to
Gary Glaenzer

well, learn to include the ENTIRE discussion that you're referring to, not just one paragraph with a one-sentence reply that makes you look like a goddam idiot, then

Reply to
Gary Glaenzer

No, I wasn't actually comparing gear ratios at all. The original poster was asking about mileage differences at certain RPMs. Although I couldn't put an actual number difference between RPMs, my point was that there was likely a significant difference between 2500 and 3000. I did mention my truck has 4.3 gears, but only in explaining how my mileage differs greatly between 55 mph and 75 mph, (which is also a significant spread in RPMs.)

And I'm sure you are a smart fellow and all and realize that wheel size matters not at all. I think what you meant was actual "tire diameter". But this is what you meant, right?......

Matt

99 V-10 Super Duty, Super Cab 4x4
Reply to
Matt Mead

. attempting to help a distressed poster..... on Sun, Sep 14, 2003, 3:53pm (CDT-2) From: snipped-for-privacy@noaddress.com (Mellowed) wrote in.....

The difference in Gear Ratios don't relate as the Motor Home has 19' wheels.

. Quick .....Martha......... get the beer out the fridge....... "Monster Motor Homes" is coming on ESPN!!!

19 foot wheels.....now there's a show......

Scribb Abel

The smartest man I ever met............. Never said a word.

Reply to
Scrib Abel

Matt, thanks for that info. I did wonder about the ratio but I thought it was because the MH was so big/heavy. thanks Tim, Looking to expand Seniors (55 + ) Daytime Pool League

Reply to
Tim Dolan

Wow, I didn't mean to cause such a fuss. For me, I'm still getting used to the thrill of having a Class A MH. But I'm just not used to practically watching the gas guage go down. I will I'm sure. It's just a whole different reference. It still bugs me when I'm getting gas and someone comes up and askes about the MPG. I still don't know if they are just jealous or sincere. I've learned to just reply by saying nicely that it gets much better milage than my house. Then I may or may not continue the conversation depending on how sincere they appeared. Thanks for your information. Tim, Looking to expand Seniors (55 + ) Daytime Pool League

Reply to
Tim Dolan

I checked my RPMs at different speeds the other day and this is what I came up with:

55 mph = 2000 rpm 60 mph = 2200 rpm 65 mph = 2350 rpm 70 mph = 2600 rpm 75 mph = 2750 rpm

I just completed a low speed (50-60 mph) trip over the mountains in WA state and back, round trip mileage of about 350 miles, and my mileage calculated out to 14.54 mpg. (Trip computer said 14.6 mpg.........very accurate as I've argued many times.) I'm guessing that without the mountain pass and a steady 55 mph run, I would have seen 15 mpg or a bit better. Recent trips on the interstate running at 75 mph have returned 12-12.5 mpg.

So my mileage difference is 2-3 mpg over a 2000-2750 rpm range. But I'm guessing the increase in RPM is only a small factor and the bigger factor in reduced mpg is wind resistance.

Granted, all this is with a 4.30 geared, 5 spd manual equipped, V-10 Super Cab 4x4 running stock 265 (31-32" diameter) tires. Obviously, (to most anyway.....), not a direct comparison to Class A motorhome!

Matt

99 V-10 Super Duty, Super Cab 4x4
Reply to
Matt Mead

Matt, Yes, I should say so. For me 2500rpm is just under 60 mph. Tim, Looking to expand Seniors (55 + ) Daytime Pool League

Reply to
Tim Dolan

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