Gas mileage question ??????

[john59]

Being new (easy way to duck the hard answers) to trailering close to 7500/7800 lbs, on a scale, with our 5th wheel, the gas mpg really jumps around with speed. The charts max me out at 8800 lbs. I had this independently checked with 2 different dealers.

Running I95 from PA to FL (N & S) the road is basically pretty flat. Not a lot of down shifting goes on. Well, not as much as I expected.

Given---Z71 Silverado, 5.3L, 3.78 rear. Some of I95 speed limit is 70 mph. If I get up in high 60's, gas mileage 7.5 mpg. A little under 60 mph, I get around 11mpg. This is a big variance. I always tow the 5'r in tow/haul.

No don't reply, get a new ZX83 Big Demon Diesel, 19 cylinder, you will get at least 15 mpg. I have to live with what I have.

What are your optimums/thoughts----speed vs mpg.

john

 

[ElementCamper]

I've found that more speed really doesn't decrease your travel time by that much. I watch my GPS, with a destination set it calculates arrival time. It takes a lot of travel at 10 mph faster to get there just a few minutes earlier.

So it depends, save gas or get there a few minutes quicker.

On the other hand, going 60 some places can get you run over.

I'm sure others will have an opinion, that's just mine. I drive a Honda Element so I'm just cruising anyway.

 

[big kahuna1]

Towing 16,000lbs plus at 65 mph I get 11.2 mpg. My tow vehicle is an 06 Dodge Dually CTD and 4.10 rear end. 65 mph seems to be the comfortable zone for my truck.

 

[BigDaddyRog]

Time is free....gas is not.

 

[john59]

So far, some good stuff. Keep it coming. Big Kahuna1 is probably on the money. Trucks have their individual comfort zone.

The more I think about it (maybe the 5.3L), the higher the speed, I believe more downshifting--- Having that tac jump 1200/1500 rpms, has to swallow gobs of petrol.
john

 

[stacktester]

I put my truck on 2,000 rpm's instead of worrying about speed. I'm doing about 65 at that rpm. If I do 70 my truck get's about 10 mpg. I get about 12 believe it or not just slowing down a few mph. My 5'er weighs about 8k pounds as well and I'm pulling with a crew cab Silverado with a Duramax/Allison 3:73 gears.

 

[all4themouse]

With our pusher it really depends on the WIND if it is windy it really does hurt you. I also notice that speed tends to effect different vehicles in different ways. Towing our enclosed trailers around with the pickups it always seems that the less stopping and going always helped out with fuel consumption. In my mind for your truck I would put a cold air intake or at least a K&N air filter and maybe a dual exhaust system. This will help with the flow and increase fuel mileage after that then I would check into one of those computer programmer things to change your shift points for towing.... I usually run manual transmissions in our trucks so I have never done the reprograming thing but I do the intake and exhaust and it always helps the fuel mileage on my trucks since 40inch tires eat some gas!!!

 

[BRDof3]

I'll trade speed for $$ any day. We've done 2 long runs with our TT since we bought it last year. We're pulling with a 4.7 V8 with 4.2 gears, and running about 12K total combined weight when fully loaded. We averaged 8.5-9.0 mpg on both trips, and that included mountains for 30-40 miles each way.

The comfort speed for my TV/TT is 62. That makes for the smoothest ride over dips or bumps, and it seems that the SUV wants to stay at that point. Using the dashboard readout as a gauge, 62 mph gave us the above average over 18 total hours of driving. Rain and wind affected it as well. If we dropped to 55, the dash reading went well above 10. Pushing toward 70 dropped it to less than 6. This was on flat road.

To be honest, the higher speed would have made a significant time difference- if I maintained it for the entire 9-hour drive. Since I know my speed will vary, I know that I won't get the full benefit of timesaving by going faster. I will, however, get the added gas expense. Overall I am better off staying at the 60-62 spot that the rig seems to like best.

 

[CampingDad]

I remember our first trip last year to FW going as fast as my truck would go to get there not even worrying about the fuel mileage. 1214.5 miles each way. I have a '04 GMC Sierra duramax towing a 30' 5th wheel. Until I got back home and realized I went through 2 extra tanks of fuel than I had figured. Our next trip I took it easy and found the sweet spot for MPG with my truck and saved going through the extra two tanks of fuel. It didnt feel like it took any longer than the year before and I had an extra $150 to spend with my family.

 

[clkelley]

60-65 seems to be my sweet spot also. While my camper weighs practically nothing (less than 2K lbs), it is the height. At 70, there is a huge amount of wind going over the cab and bouncing against the front of the trailer.

I get 13-14 going 60-65 and only get about 10.5 - 11 going 70-75

 

[LarryJ]

Being new (easy way to duck the hard answers) to trailering close to 7500/7800 lbs, on a scale, with our 5th wheel, the gas mpg really jumps around with speed. The charts max me out at 8800 lbs. I had this independently checked with 2 different dealers.

Running I95 from PA to FL (N & S) the road is basically pretty flat. Not a lot of down shifting goes on. Well, not as much as I expected.

Given---Z71 Silverado, 5.3L, 3.78 rear. Some of I95 speed limit is 70 mph. If I get up in high 60's, gas mileage 7.5 mpg. A little under 60 mph, I get around 11mpg. This is a big variance. I always tow the 5'r in tow/haul.

No don't reply, get a new ZX83 Big Demon Diesel, 19 cylinder, you will get at least 15 mpg. I have to live with what I have.

What are your optimums/thoughts----speed vs mpg.

john

If you have ST trailer tires they are only rated for 65 mph unless you over inflate them and most rims won't take that extra pressure so you are basically limited to 65mph max. If you tow a lot above that IMHO this is why we read a lot about blowouts causing major TT damage from flying alligators off their speed limited tires. I always keep my speed down to around 60mph unless for short bursts to get around a big rig, etc. Speed is the biggest factor in MPGs at highway speeds. Lower speed better MPG.

Larry