Recs for better MPG pulling trailer?

[D_R_C]

How you can tell if you have ping is to find a large grade and boogie up it.
This is when you'll know.
My gasser 1995 Class A Motor Home Ford F53 chassis with a 460 cu. in. with a 80 gallon tank, Ford and everyone shop states to only use regular.
THEY ALL SAY DO NOT USE PREIMUM
I'm sorry but they are my vehicles, I drive them and know what's best to use and I get the best results with Premium in everything.
When I used regular which was only 2 times over the past 18 years it pinged like crazy pulling grades and I lost 1-1 1/2 mpg using regular.
When I'm only getting 6 mpg in my M.H. with premium as is and it drops to 4 1/2 with regular, this sucks.
Premium and only premium is used in every gas vehicle (5) and gas engines I own, including my 91 Geo Tracker, lawn mowers (2), generators (3) etc. etc.
Spend the extra 20 or so cents your vehicles will be happier, besides they will run much better on Preimum.

 

[Stevereno]

We took the travel trailer out for the weekend to a park about 125 miles from home. Fueled up the Tahoe with 89 octane for the drive up, got about 9.3 MPG per trip computer. Refueled with 87 octane for the drive home, got 9.2 MPG per trip computer. Had plenty of uphill grades that would take 1200-1500 RPM increase to maintain speed (60-65 MPH most of the time) and had no noticeable pinging/knocking. From our experience to date, I just can't see paying the additional 40 cents or so per gallon for 89 octane.

 

[D_R_C]

Where are you buying gas that there is 40 cents per gallon difference between reg and mid grade. Out west at this time $3.59 for reg, $3.69 mid grade, $3.79 premium.
Besides what outside temps are you in ? When your in +100 degrees pulling grades you just might get ping.
Grades that are in the 6-8% range for several miles.
Besides if you want true actual mpg you really should top off the tank each time and hand calculate instead if going by the DIC.

 

[JennaBear]

That and the computer needs time to learn the 89. Just one tank won't cut it, you still had 87 in there.

Sent from an ice cream sammich.

 

[Zed 71]

Hey Jenna, when I had my truck tuned by Justin quite some time ago, I did not think I would be using the tow mode (had him change it to performance mode).

We are now towing a 3,600 lb trailer. Do you think there is any benefit changing the button back to tow mode?

Thanks in advance.

 

[Helidriver]

I made a 400 mile round trip from Houston to Marble Falls last weekend pulling a 6-7k car trailer. On the way up I averaged (hand calculated) 10.5 mpg with the cruise control set to 65. On the way home I was able to get nearly 12 mpg without the cruise control but still driving 65.

 

[JennaBear]

Hey Jenna, when I had my truck tuned by Justin quite some time ago, I did not think I would be using the tow mode (had him change it to performance mode).

We are now towing a 3,600 lb trailer. Do you think there is any benefit changing the button back to tow mode?

Thanks in advance.

He can definitely change it back to stock tow/haul if you like. Just shoot him an email to [email protected].

 

[zzpw3x]

I've done thousands of miles towing 6000 lbs and never heard a ping with 87 octane. Maybe 1/2 of those miles were before I had a tune, and mostly in the summer.

 

[JennaBear]

Pinging is not always audible, but again, if the quality of fuel is decent and depending on your engine, it is possible that you have none.

 

[D_R_C]

I always suggest digging a little deeper in the pocket book and try premium for a couple tanks, one will not do. The computer takes a little time to adjust.
Everyone I know that's tried this had always said performance and mileage gains was noticed.
But if the budget is tight most would rather save a buck than have a little better running vehicle.

My previous vehicle 06 Denali 6.0 I had a Hypertech they tune for regular but I tried premium and it ran much better and it gain a easy .5+ mpg.
Arizona's gas and diesel does lack in quality.
With my EFI tuning doing a data log it appeared I was running regular but I always run premium.
I even tried Chevron and Shell this did not change anything.

 

[Stevereno]

Where are you buying gas that there is 40 cents per gallon difference between reg and mid grade. Out west at this time $3.59 for reg, $3.69 mid grade, $3.79 premium.
Besides what outside temps are you in ? When your in +100 degrees pulling grades you just might get ping.
Grades that are in the 6-8% range for several miles.
Besides if you want true actual mpg you really should top off the tank each time and hand calculate instead if going by the DIC.

We live in Montgomery County, NE of Houston, TX. 40 cent difference was a bad example. That's what my wife reported that she paid wherever she filled up her Tahoe before our trip. I believe it's more like 15 cents for each upgrade in octane from what I have seen lately. We're currently paying around $3.29 per gallon for 87 octane. Outside temps vary of course but we were in mid-60's to mid-70's on our most recent trip. It's warmer now and the summer heat is just around the corner.

I know not to rely on the trip computer for true gas mileage, was only using it for convenience to show the relative difference between normal driving and towing or results for 87 and 89 octane (limited test I know). I am logging my mileage for every tank in my daily driver and I see almost 10% error (on the high side) in what the trip computer indicates.

 

[Zed 71]

With my EFI tuning doing a data log it appeared I was running regular but I always run premium.

I even tried Chevron and Shell this did not change anything.

Just curious what you mean by the data log appeared you were using regular, but you were actually running premium. That is odd especially when you indicated that you switched to top tier gas stations. Seems like a tuning issue and did you ask any input from your tuner?

---------- Post added at 10:34 AM ---------- Previous post was at 10:34 AM ----------

He can definitely change it back to stock tow/haul if you like. Just shoot him an email to [email protected].

Thanks Jenna for the response .

 

[JennaBear]

We live in Montgomery County, NE of Houston, TX. 40 cent difference was a bad example. That's what my wife reported that she paid wherever she filled up her Tahoe before our trip. I believe it's more like 15 cents for each upgrade in octane from what I have seen lately. We're currently paying around $3.29 per gallon for 87 octane. Outside temps vary of course but we were in mid-60's to mid-70's on our most recent trip. It's warmer now and the summer heat is just around the corner.

I know not to rely on the trip computer for true gas mileage, was only using it for convenience to show the relative difference between normal driving and towing or results for 87 and 89 octane (limited test I know). I am logging my mileage for every tank in my daily driver and I see almost 10% error (on the high side) in what the trip computer indicates.

I can tell you that based on tuning trips Justin has done in San Antonio and Houston, they are notorious for poor gas quality.

 

[D_R_C]

Just curious what you mean by the data log appeared you were using regular, but you were actually running premium. That is odd especially when you indicated that you switched to top tier gas stations. Seems like a tuning issue and did you ask any input from your tuner?.

Because the tuner tuned it with timing like he always does, it hit the ping/knock sensors to soon shown by the data log I did.
So he took out a little more timing I did another data log, pretty much the same results, knock sensors.
He then asked if I was running premium which that is all I've ever used.
He back out timing a little more, another data log better results.
FYI using Chevron mileage and performance was about the same as Fry's fuel 13.1-13.3 with Shell performance was ok but it lost 1 mpg down to 12.3.
Pretty much the same drive everyday.
My tuner wants another data log after the temps hit over 100* to verify the tuning is good.
It'***** 100* but I'm going to wait until at least 105+ which is real soon.
Now after 4 tanks, 4th one I'm back to using Fry's fuel my mileage is @14.0.
I've been topping out the tanks to get actual gallons used, I'm not guesstimating.

 

[JennaBear]

Depending on where you live, there are premium octanes that are very low quality. AZ for instance, has horrible gas across the board.

 

[D_R_C]

The above statement is sadly true for regular, mid-grade, preimum gas and diesel.
Power Services even suggested trying to double or triple the Diesel Kleen additive on my Dmax to increase the cetane. This was no help with mileage.
All it did was raise the diesel cost even more per gallon and put more money back in Power Services pocket book.