i'm not claiming that engine restore is a totally worthless product...i only have my own experience as backup. i did a compression test onmy 92 bonneville a couple months ago, 145-150 across the board, couldn't believe the compresssion was that good on a 197,000 mile car. put in the RESTORE product at my last oil change. now at 199,000 it SMOKES heavily at startup and for the first 10 or so miles. never happened before the RESTORE application. Out of curiousity i ran another compression test...120-130 across all cylinders now, still not terrible, but certainlynot expected after only 2,000 miles. oil consumption which was never an issue before (maybe 1/8 qt in 3,000 miles) is now up to 2 qts in 2,000 miles. Car has only seen Castrol GTX high-mileage 10w30 for the last 60,000 miles.

anyway, if you want to use RESTORE go ahead. maybe your luck will be better than mine. from now on though i'm done with additives, i'll just stick to a seafoam treatment every 12K or so.

 

Superchips advances timing under certain conditions, but it still won't help the timing that is pulled during the pcm's torque management strategy.

You could also try a small cam (not as small as the factory cam)w/ a little tighter lobe seperation than 115.

 

CVT transmissions don't shift. There are two clutches that expand and contract to get different gear ratios, so there is no shifting. IT's the same setup that is in snowmobiles.

 

A quick repeat
that high rolling resistance tires
can be the cause of early downshifting on hills
....the original question in this post.

17 horsepower is needed on a 5500 lb 2nd Gen Ram with tires of rolling resistance 0.007 to roll the four tires at 75 mph.

59 horsepower is needed on a 5500 lb 2nd Gen Ram with tires of rolling resistance 0.04 to roll the four tires at 75 mph.

Someone not afraid of math
and a stopwatch
can actually test their own truck for both
tire rolling resistance and aerodynamics
with this Java applet at an archived web page:

http://web.archive.org/web/200408030...DownCalcs.html

Divide the 34.5 square feet of a 2nd Gen Ram
or 35.1 square feet of a 3rd Gen Ram
by 10.8 to convert square feet to square meters

The Cd you find this way
should be in the range of 0.38 to 0.53
depending on the model year of the pickup, 4x4, tonneau, bug guards, etc

The rolling resistance will be anywhere from
0.007 from the best ribe style highway tire with half the tread worn off,
to 0.04 for 'mudder style tread' off road tires

You can get even more accurate results by running the test at two different weights, like with only the driver, then with 1500 lbs in the bed.

 

Nice info:

And I thought I had too much time on my hands.

 

Thanks Hank, good info.
In general what type of tread pattern has the lowest rolling resistance?
Is there much difference in rolling resistance between "P" series tires vs. "LT" with a similar tread style?

 

I am planning on adding a Hypertech programmer, headers and dual exhaustto my truck in the future along with some slotted/cross drilled rotors.
The rotational mass wt. at the wheels/ axlesare a good performance measure I have learned as well.

 

A new MPG law for 'Corporate Average Fuel Economy'
or CAFE is about to be passed
and supposedly it has a section that requires
customers be told what the rolling resistance of the tires
they are about to buy is.

http://www.reifenpresse.de/CDML007/e...mp;RecID=12990

but in the past this kind of consumer information
gets killed quietly in 'conference committees' late at night.

Cut from the Ram MPG FAQ tire section:
----

TIRE CHOICES for BETTER MPG

Increasing the air pressure in your tires, and picking a narrow 'rib tread'
commercial delivery truck type tire that has low rolling resistance
definitely will help MPG.

Raising the air pressure by 15 psi to the max 70 psi in Goodyear Wrangler
HT 235/85R16E tires increased my mpg by +1 in a 311 mile
test run - but the ride was bone jarring. A narrow, highway rib tire like the
HT gives the lowest rolling resistance. Wide, aggressive tread tires can be
three times harder to roll. It might pay to have a 4 tire set for the weekday
commute, and a weekend mudder wide tire set.

Several Cummins Diesel Ram owners have reported that buying special
wheels and converting to 19.5 Commercial truck tire designs have
improved both MPG and tire tread life - but these tires are generally
heavier. RicksonTruck is one such special wheel seller:

http://www.ricksontruck.com/

Consumers Reports is the only organization I know of that tests for rolling
resistance of tires but even they do not report the Crr number.
Quote from CR:
" Fuel mileage at a price. Some tires roll with less drag than others. The
lower a tire's rolling resistance, the more fuel you can save. Those savings
can be significant. {Pickup and SUV} Tires with the lowest rolling resistance
delivered nearly 2 mpg more at a steady 65 mph in our highway tests {2003
four-wheel-drive Ford Explorer XLT 4x4} than those with the highest rolling
resistance. The catch: While some high-scoring tires had low rolling
resistance, most tires with the lowest rolling resistance also had lower
overall scores."

In their 11/2004 Pickup & SUV tire test CR the
lowest rolling resistance tires rated 'excellent' were the:

Bridgestone Dueler H/T (D684)
Michelin Cross Terrain
Continental ContiTrac
BF Goodrich Radial Long Trail T/A

The Pickup & SUV tires with the worst rolling resistance were the:

Pirelli Scorpion STA
Kelly Safari Signature
Yokohama Geolander H/T-SG051

A tire with a 'very good' rolling resistance and high scores in other handling
and braking tests was the Hankook DynaPro AS RH03

Hankook recently announced that they had spent $10 million developing a
tire called the fx-Optimo that has even lower rolling resistance and can
give up to a 3% MPG improvement:

http://www.moderntiredealer.com/t_in...p;storyID=5961

In another test of "All Season" tires in November 2005,
CR rated these tires as 'excellent' for low rolling resistance:

Michelin X Radial DT
Michelin Agility Touring
Michelin Harmony
Hankook Mileage Plus GT H707
Kumho Touring 795 A/S
Toyo 800 Ultra
Sumitomo HTR T4

In the same November 2005 issue
'All Terrain' tires were also tested
but only the
Continental ContiTrac TR
got an excellent rating for low rolling resistance in this group.

The California Air Resources board is pressing the tire companies to make
rolling resistance measurements on tires freely available to the public by
2008, one of the few reasonable things CARB has ever done in my opinion

The lower profile 17 and 20 inch tire designs used on the 2003-2005
5.7Hemi Rams have a 'sticker' tire tread and higher rolling resistance than
earlier year Rams. It is probable that if a manufacturer makes available a
235 85 R17 tire in Load Range E it would be lower rolling resistance
than the stock tires and might improve MPG by 1-2 at 70 mph.

The 2006 Ram press release says the new model will have 'low rolling
resistance tires.'

In April 2006 the "independent and non-partisan" US National Academy
of Sciences completed a report on the rolling resistance of tires and how
MPG for the entire country might be easily improved if tire makers
increased their research into how to make tires roll even easier.
The 'meat' of this report starts about page 50 at this weblink:

http://www.trb.org/publications/sr/sr286.pdf

 

Lots of great input! I plan to start going threw all the minor tune up stuff this weekend. The previous owner has already been into the gears on the rear and removed the tab so Im not sure whats in there....@ 70mph I run about 2000 rpm "265 75 R16".

 

look on the underside of your hood, near the grill. there should be a sticker there that tells you your stock gearing and some other options