The other day strolls in to my local auto shop....

Where they had Shell ultra for diesel engines on sale
Shell ultra for petrol engines was it's usual price...

Now aren't they just the same stuff in a different tin?

all the numbers matched..... both 5W-40

Calling all oil boffins......

Plums...

 

They have different additives and detergents.

 

HI THER NOT THE SAME AND DONT PUT IT IN YOU CAR

 

Are you sure there not the same?

Only a few years back Mobil 1 used to state petrol or diesel on the same bottle?

Plums.

 

Any one else?

 

It's likely they are the same, do they both have the same ratings on the label?
Can only find 1 data sheet for shell helix ultra 5w-40 and say's suitable for petrol or diesel engines.

 

Both the same Visc numbers....

Plums.

 

the viscosity rating is just that, a measure of how the iol flows at given critera.

The bit you need to know is what the oil can do,

Diesels run at higher compression ratio,s and need an oil that can cope with the crap the process creates, and it has to be able to cope with removing the byproducts without contamininating the rest of the system.

petrol uses oils that perform in a different method.

I,m no expert, but i would say dont use a diesel oit in a petrol car, and vice versa

Mart

 

As above Diesel oils have different levels and types of Detergent.. They will probably do little if any harm to your petrol engine, but is it worth the risk for a couple of quid?

 

You need to check the approvals on the rear label also, should be something like this,

Performance Specifications
Shell Helix Ultra exceeds the requirements of all major car manufacturers and the following industry
standards:
API SL/CF
ECI SAE 5W-40
ACEA A3-98, B3-98 & B4-98
Rover Registered
VW 500.00, 502.00, 505.00 (SAE 5W-40)
Japanese Engines Qualified
Porsche Approved
BMW Special Oils listing and Long life Oils listing (5W-40)
Peugeot-Citroen Meets requirements of PSA E-98 extended drain (level 2 for application)
Mercedes Benz Sheet 229.3
Ferrari Factory Fill and Sole Service Fill Recommendation

Applications
• all naturally aspirated, fuel injected, turbocharged and multivalve passenger car engines fuelled by either gasoline, diesel or LPG